Easy money, REP, and Speed cards:
To get a lot of money, REP, and Speed cards quickly, complete short events. Since all events give almost identical rewards regardless of the difficulty, just keep repeatedly completing the shortest events. The fastest event in the game is the "Drifting The Block" drift trial. It becomes unlocked early in the game, when you do drift trials for the first time. It is the perfect farming spot for money, REP, and Speed cards. This event can be completed in 90 seconds, and since it is a circle, you finish at the start and can instantly replay it. Each time you finish the drift trial, you will get approximately 12,000 credits (17,000 credits if you sell the Speed card), 120,000 REP, and a Speed card. You can get approximately 3,600,000 REP and 510,000 credits per hour using this method.
Keep replaying the "Hyperspace Circuit" race. It becomes unlocked during the final act, at the end of the game. It gives 31,000 credits (if you sell the Speed card), 144,000 REP, and a Speed card. The event only takes three minutes to complete, including loading times and transition screens (with a fully upgraded car). It also immediately puts you back at the start of the event. You can get approximately 2,880,000 REP and 619,980 credits per hour using this method.
Unlock Derelict cars
Collect the five hidden Derelict car parts for a Derelict car to unlock it. Each Derelict car requires you to have defeated a different league boss. After defeating a league boss, you will get clues for the five Derelict car part locations of a certain car. In the map menu, select the "Derelict" tab to view the clues. It shows a drawing with outlines of the streets where the Derelict parts are located. You normally would have to look at the in-game map and compare it with the drawing, but the videos below show all the Derelict part locations. The Derelict cars are special because they can be upgraded to the maximum level without the level caps normal cars have. After upgrading a Derelict car to Performance Level 300, it unlocks a Super Build for more extreme visual customization. After restoring a Derelict car, you can also choose which category you want it to be (Race, Drag, Drift, Runner, or Offroad). It is recommended you choose a different category for each unique car. None of the Derelict car parts are missable, but they will not spawn until you have defeated the corresponding league boss. Assembling one Derelict car unlocks the "One Man's Trash" trophy, and upgrading it to Performance Level 399 unlocks the "Another Man's Treasure" trophy.
Chevrolet Bel Air 1955
To collect the five Derelict car parts for the Chevrolet Bel Air 1955, you must first complete the Runner quest line.
Chevrolet C10 Stepside Pickup 1965
To collect the five Derelict car parts for the Chevrolet C10 Stepside Pickup 1965, you must first defeat the "Riot Club" (Big Sister) league boss (Drag quest line).
Ford Mustang 1965
To collect the five Derelict car parts for the Ford Mustang 1965, you must first defeat the "La Catrina" league boss (Race quest line).
Nissan Fairlady 240ZG 1971
To collect the five Derelict car parts for the Nissan Fairlady 240ZG 1971, you must first defeat the "Udo Roth" league boss (Offroad quest line).
Volkswagen Beetle 1963
To collect the five Derelict car parts for the Volkswagen Beetle 1963, you must first defeat the "Shift-Lock" (The Underground Soldier) league boss (Drift quest line).
All billboard locations
Go to the indicated locations to smash through all 30 billboards and get the "Does Not Obey" trophy. Each billboard needs to be smashed through using a ramp. Most billboards do not require powerful cars to reach -- so you can get this trophy early with cars under 200 power. The 30 billboard locations are split into three sectors. They are collected from top to bottom, going through the map from left to right.
Getting 3 stars on "Eject Button" Jump challenge
The "Eject Button" Jump challenge is one of the hardest jumps in the game, and requires a car that is made for jumping and some practice and luck with the ramp. A good car to use is the Porsche Panamera Turbo with the Offroad build. Mainly go for jump speed cards. These will increase your airtime, and you should get it above 9 or even close to 10. The "Eject Button" Jump is especially difficult because you have to hit top speed while going against traffic and squeezing through a narrow spot to hit the ramp. This takes some practice.
Easy "1500 bhp... Easy" achievement
The Koenigsegg Regera is unlocked for purchase after completing the story. Buy the "Race" version at the Race dealership, not the Drag version. Winning Drag races with the Drag version does not unlock the achievement. The Regera costs 794,205 credits. You can farm credits by replaying events and selling cars and performance upgrades you no longer need. Opening shipments is also a quick way to get credits. Play the "Midnight Run" race. It is in the Desert area in the middle of the map, and the shortest race in the game. It only takes one minute to complete. You must place first in the race without hitting any other cars, guard rails, walls, rocks, etc. to get the "1500 bhp... Easy" achievement. You are allowed to hit street signs since they do not damage your car. If you hit something other than street signs, restart the race to try again. It may take a few tries. Most importantly, try passing all opponents at the first bend in the road. The trickiest part is not hitting any opponents as they tend to drive recklessly. The sooner you take the lead, the better. You still need to drive fast though. Otherwise, your opponents will catch up to you and potentially crash into you from behind. Just practice the race a few times to get the hang of it.
Easy "Driving The Incredible" achievement
First, progress to the end of Chapter 4, which is when the BMW M5 becomes available for purchase at the Drift Dealership (dealership is marked on the world map with a green icon). The BMW M5 costs 112,905 credits. Make sure to buy the M5 and not a different BMW. Only the BMW M5 works for this achievement. Next, play "The Drift King" drift trial. It is the final drift race in the game, unlocked in Chapter 4 after completing all other drift trials. It is the longest drift trial, where you can earn the most points. It may take a few tries to get 350,000 points. If you are short on points, pause the game before the finish line and select "Restart" to try again. If you are having difficulties, try upgrading the car. Your drift score is a combination of speed and drift angle. There is also a multiplier. The multiplier increases whenever you are drifting and drops when you are not (so long drifts are beneficial). However, using nitro will freeze the multiplier -- so use nitro between drifts to keep the multiplier up. Drift at every bend in the road, not just at big turns. At high speeds, even just tapping the handbrake for a split second can get you 10,000+ points on a straight road. With some practice and an upgraded BMW M5, it is not too hard to do this.
Easy "Hyperspeed" achievement
To reach the top speed of 240 mph, you need to be near the end of the main story and unlock a car that can be upgraded to 399. Try using the Koenigsegg, which is quite expensive but allows you reach the 240 mph without any upgrades. There are a lot of other cars that can reach that top speed with speed upgrades.
Accomplish the indicated achievement to get the corresponding number of Gamerscore points:
1500 bhp... Easy (25 points): Win a race in the Koenigsegg Regera without damaging it.
Aces High (20 points): Complete all Jumps.
Active Lifestyle (40 points): Get a 3 Star Rating on all the Activities in the game.
A Daily a Day (15 points): Complete your first Daily Challenge.
Another Man's Treasure (25 points): Get a Derelict car to 399 Performance Level.
Perfect Shift (20 points): Win a Drag Race round by performing only perfect shifts.
Carbon Cartel (10 points): Equip a full setup with the Carbon brand.
Comeback is Real (10 points): Be last during the final lap of a race and still win.
Cover Stars (40 points): Own the BMW M5 2017, NISSAN Skyline GT-R (1999) and Chevrolet Bel Air.
Does Not Obey (20 points): Smash your way through all the Billboards.
Driving the Incredible (25 points): Get a score of over 350,000 points with the BMW M5 2017 during a Drift Trial event.
First Strike is Deadly (15 points): Complete all 5 events in a single Speedlist.
Flat-Out (20 points): Complete all Speed Runs.
Friendly Competition (15 points): Beat your first Autolog Recommendation.
Hope and Glory (10 points): Equip a full setup with the Americana brand.
One Man's Trash (25 points): Assemble a Derelict car.
Outlaws on the Rise (10 points): Equip a full setup with the Outlaw brand.
Scrappy Racer (10 points): Win an event using a Derelict car.
Sideways Style (20 points): Complete all Drift Zones.
Still Not Lovin Police (40 points): Take down 100 cop vehicles.
Tech Mate (10 points): Equip a full setup with the NexTech brand.
The Artist (20 points): Unlock all Visual Customization points.
The Climb (40 points): Complete 10 events in Ranked Speedlists.
The Strategist (25 points): Grind a previously won narrative event for Speed Cards.
The Mogul (20 points): Buy all available Garage spaces.
Tinker, Tailor, Racer, Fly (10 points): Win a Race Event with a modified live tuning setup.
Top Dog (40 points): Reach REP level 50.
Training Wheels Off (10 points): Reach REP level 2.
Wherever I May Roam (40 points): Beat all 4 Roaming Racer bosses.
Who Runs this Town? (60 points): Win all the events and beat all the Roaming Racers in the game.
You've Got the Need (20 points): Complete all Speed Traps.
Under the Hood (10 points): Equip a full setup with the Chidori brand.
Supercars for Breakfast (25 points): Beat all the members of the 1% Club roaming racers league in the Nissan GT-R.
Additionally, there are 20 secret achievements:
Against All Odds (60 points): Bring down The House.
Aki Kimura (5 points): Defeat Noise Bomb league boss Aki Kimura.
Big Sister (5 points): Defeat Riot Club league boss Big Sister.
Faith Jones (5 points): Defeat Free Ember Militia league boss Faith Jones.
Gallo Rivera (5 points): Defeat Silver Six league boss 'Gallo' Rivera.
Holtzman (5 points): Defeat Hazard Company league boss Holtzman.
Hyperspeed (10 points): Hit 240 mph using any car.
All In (20 points): Collect all of the Gambler's Chips.
La Catrina (5 points): Defeat Graveyard Shift league boss La Catrina.
Mitko Vasilev (5 points): Defeat Diamond Block league boss Mitko Vasilev.
Natalia Nova (5 points): Defeat One Percent Club league boss Natalia Nova.
Back in the Game (20 points): Reassemble the crew.
We Got This (20 points): Complete the Highway Heist.
Double or Nothing (20 points): Steal two gold-plated cars.
Spread the Word (10 points): Win your first event against a Street League.
I Fought the Law (20 points): Escape the Skyhammer.
Udo Roth (5 points): Defeat League 73 league boss Udo Roth.
Underground Soldier (5 points): Defeat Shift-Lock league boss The Underground Soldier.
Welcome to Fortune Valley (10 points): Complete the Prologue.
Pranked (15 points): Beat Jesse Wellens in an Outrun Race.