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
Own 30 cars
Win Teruko Nakamura's car
Win Vassily Rykov's car
Win Payton Hills' car
Buy Gustav Reuter's “Koenigsegg Agera RS Custom”
Complete an endurance race without changing your tires
Own 15 cars
Win Primo Biondi's car
Win the Porsche 911 Type 930
Finish a race on less than 2% fuel
Beat Gustav Reuter
Beat Primo Biondi
Buy a category D car
Beat Teruko Nakamura
Buy a category C car
Own 5 cars
Beat Vassily Rykov
Buy a category B car
Beat Payton Hills
Add a body part to one of your cars at least once
Change the rims of one of your cars at least once
Put back a part of lesser quality
Complete 25 races with no collisions
Build the Wind Tunnel
Build the Body Workshop
Change the look of your Performance Shop
Install 10 items in your Performance Shop
Earn your first Million Credits
Complete 25 solo races
Install 5 parts on your car
Build the Tire Workshop
Change the color of one of your cars at least once
Visit another player's Performance Shop
Join or create a Club
Buy a category A car
Drop out of a race
Beat Ken Cole
Put 5 stickers on the same car
Build the Mechanic Workshop