HOT WHEELS UNLEASHED 2 - Turbocharged

Given the sheer number of AcceleRacers themed DLC packs in the game, getting this achievement can be rather confusing for someone who bought all of the DLCs or a premium edition of the game.

The cars you need to upgrade for this achievement are the ones actually given by the DLC that is simply called "AcceleRacers Expansion," which are:

• Rat-ified
• Chicane
• Spine Buster
• Vert's

You don't need to upgrade all 4, nor do you need to buy any Skills. Simply pick one of the cars and upgrade it to Ultimate Tier using either coins or wrenches.