Car is one of the Yoshi transformations featured in Super Mario World 2: Yoshi's Island and its remake Yoshi's Island: Super Mario Advance 3. It is granted by touching a Morph Bubble depicting a car. The transformation is alternatively named Vehicle.
In Super Mario World 2: Yoshi's Island

The transformation appears exclusively in the level Lakitu's Wall, so it can only be used by Red Yoshi. In Yoshi's Island: Super Mario Advance 3, it also appears in the Go! Go! Morphing! stage, where it is used by Green Yoshi. Car Yoshi is smaller and moves faster than regular Yoshis, but the main purpose of the transformation is getting through tight spaces, similar to the Mole Tank. Car Yoshi can also extend its wheels to avoid certain obstacles. It can also defeat several enemies by simply driving into them.
Both the original and remake consist of unused sprites of the other Yoshis in their Car form. The Car Yoshi artwork shows Cyan Yoshi under this transformation, although he never gets the opportunity to within the games themselves.
In Super Smash Bros. Brawl
Car Yoshi is a sticker only usable by Yoshi, and it increases his tail attack by 7. The sticker itself depicts the Car Yoshi transformation, but adds some touch ups such as yellow lighting, akin to other artwork for Yoshi's Island: Super Mario Advance 3.