Here is the full list of all 42 Gear.Club Unlimited 2 - there are Ultimate Edition achievements.
Win the Ford GT40
Reach 400 km/h on the Le Mans circuit
Win an Endurance Championship
Complete an endurance race without changing your tires
Own 30 cars
Visit another player's Performance Shop
Buy Gustav Reuter's “Koenigsegg Agera RS Custom”
Beat Gustav Reuter
Win Primo Biondi's car
Beat Primo Biondi
Install 10 items in your Performance Shop
Buy a category D car
Win Teruko Nakamura's car
Beat Teruko Nakamura
Complete 25 races with no collisions
Own 15 cars
Finish a race on less than 2% fuel
Buy a category C car
Win Vassily Rykov's car
Change the look of your Performance Shop
Beat Vassily Rykov
Buy a category B car
Win Payton Hills' car
Put back a part of lesser quality
Put 5 stickers on the same car
Earn your first Million Credits
Win the Porsche 911 Type 930
Beat Payton Hills
Build the Body Workshop
Build the Wind Tunnel
Complete 25 solo races
Change the rims of one of your cars at least once
Add a body part to one of your cars at least once
Own 5 cars
Drop out of a race
Change the color of one of your cars at least once
Install 5 parts on your car
Build the Tire Workshop
Join or create a Club
Buy a category A car
Beat Ken Cole
Build the Mechanic Workshop