Unicorn Easter Egg:
If you start at the Pit Mines west of New York City and drive a Dirt Spec vehicle into the forests that are to the west of the mine you will find a unicorn in an open field.
Area 51 and UFO Easter Egg:
At the Mountain States area travel to the edge of the Mojave Desert. Just as you enter the Western Shrub-Steppes you will come across a military base north and slightly to the west of the Speed Skill 91 challenge. At the military base you will be able to see a large silver UFO inside a fenced-off area.
Bigfoot Easter Egg:
You can find an 8ft tall Bigfoot any time of day by travelling to the Northern Cascades, East of Seattle in a Dirt Spec vehicle.
Scrap Salvager Achievement:
In total there are 20 Wreck Parts in the Midwest area. Finding ALL of them will unlock the 'Hotrod HuP One' hidden car and earn you the 'Scrap Salvager' Achievement. Once you have picked up a collectible your progress will be saved automatically and after finding the last Wreck Part you must return to the HQ to unlock the car.
Unlock HuP One Hotrod:
When you have collected ALL 20 wreck parts in the Midwest region you will unlock this Street Spec Hotrod at your headquarters. Wreck Parts show up as blinking icons on the in-game map.
Unlock Dirt Hotrod:
When you have collected ALL 20 Wreck Parts in the East Coast region you will unlock the Dirt Spec Hotrod at your headquarters. Wreck Parts show up as blinking icons on the in-game map.
Golden Plates Challenge Codes:
Login at the Ubisoft Golden Plates page and enter the following Golden Plates Challenge codes to receive various rewards that includes paints and rims.