Why don't they make 'em like this anymore?
This is how a racing game is made. Lots of (80) tracks to unlock, beautiful smooth-running FULL 3D graphics, good controls, and saving after every race. Fantastic.
Look, if you can find a copy of this either new or (more likely) used, pick it up. It is one of the best hand-held racers for the GBA, hands down. In fact, if gives many of the DS racing titles a serious run for the money. No clipping, a co-pilot who shouts out turn directions (easy left, hard right, etc.), decent rumbling engine sounds, and background graphics that are so lovely that I find myself repeatedly distracted by the view to the point of missing a turn and losing the race. Luckily, you can re-start without any penalty any time, so the frustration level stays low, unlike what you encounter with, say, most Need for Speed titles.
If you like racing games, you really really need to scoop a copy of this if you can find it. Trust me, you won't regret it.