The Vita has seen a few efforts at fun car racing. Apart from the awesome MotorStorm and Sonic Racing, none really seem to have taken hold. Table Top Racing is probably the closest we've come to micro-car fun recently.
Looking to change all that is HTR+ Slot Car from Brazilian developer QUByte Games. The game has hit mobile, PC and Mac in the past, but really looks the part on a Vita screen. If it plays as good as it looks, then hopefully the company will bring its other titles to Sony's handheld.
There are 20 tracks, 3 skill levels, a track editor and plenty of bonuses to unlock.