Steam Trading Cards
From Carnage Racing Wiki
Steam Trading Cards are virtual cards obtained by playing Carnage Racing and trading with other players. There is a total of six cards needed to complete the set and craft a Carnage Racing badge. Three of these can be obtained by playing Carnage Racing, whilst the others can be obtained by trading with other players.
Steam Trading Cards
Foil Trading Cards
Foil cards are rarer than regular cards. They can be crafted to produce a foil badge.
Rewards
When crafting the badge, players will also receive random rewards which can either be used for your Steam account, or sold on the Steam Market.
More information: Steam Trading Cards/Rewards