Touch Arcade:
Two of my favorite things about the iPad include just how much you can see on screen at once and how well this increased screen size goes with single-device multiplayer. Danger Derby [$4.99] is a top-down racing game that fully embraces these two strengths of the device. Gameplay is a little on the basic side, but as many developers have proven already with games like NimbleBit's Omium [99¢], solid local multiplayer can make even the simplest of games can be a ton of fun.
There aren’t that many top-down racers for the iPad, so Danger Derby certainly stands out in the App Store. In the standard Arcade Mode, you select your car and then it’s off to the races. The earliest track is simple (a basic oval), but the track design progresses in difficulty rapidly. All told, there are eight tracks available, which should provide plenty of challenge for quite a while.
Pocket Gamer:
There hasn't been a great Micro Machines topdown racer since... well the original Micro Machines, and while Cobra Mobile's Danger Derby isn't exactly the same sort of game, it certainly offers similar thrills.
Released just for iPad, and including a neat two player on-device multiplayer option, it's what Cobra calls a Race and Chase game, that has you zooming around eight different curvy tracks against three other cars.