MiniDrivers had Steam trading card support added on September 8, 2015. There are 9 cards in the series, and you'll receive 5 cards at random for purchasing and playing the game.
Trading Cards
Freeze-o-Kimi
Fight or Run
Who will win?
I am the champion
El Nano
Big Bang Smurf
Finger Boy
The Ice Man
Hammer Time
Foil Cards
Freeze-o-Kimi
Fight or Run
Who will win?
I am the champion
El Nano
Big Bang Smurf
Finger Boy
The Ice Man
Hammer Time
Badges
Booster Pack
Emoticons
Profile Backgrounds