I firmly believe this is an unpolished and unfinished project that has left players in good standing lose races, single-player or multiplayer, due to track design and physics. Perhaps if we post a list of glitches in the game, we can find where they are and try to avoid them for future reference.
Seaside Hill: On the first hill, you can nosedive into the road and be stuck.
Super Monkey Ball: In the green portal approaching the finish line, it's possible to be sucked into the wall and do a complete 180 or 90 degree angle into a side-wall.
The only flaw I can think of right away is, of course, the snake mouth in Adder's Lair.
Huge problem. My friend and I experienced it as well.
If you take the left path in Adder's lair, you won't run into the snake mouth problem. Which you should as the left path is way faster than the right path.
Also, in Burning Depths as Ulala. At lap 2 after the long right water section before the path splits, if you take the right path, Ulala will slam right into an invisible wall the moment your about to get back onto the road and it will cause her vehicle to fly off in the wrong direction and possible ruining your race. The wall seem to disappear after the 1st hit. You can avoid this problem by taking the quicker left path.
Driving a PC racer with the keyboard is about as effective as typing an e-mail with your car's steering wheel. ~ Brian Ekberg