Just played for almost an hour, loved it. 2-Players first, then 3-Players, we couldn't stop laughing.

Great game!
As for the Internet multiplayer part, I'm not sure I like the idea. I think you'll manage to make the movement lag-free and fun, but I believe this game lives from the "we're all on the same keyboard and we can hear each other laughing"-feel. Dunno, might be wrong.

Can you make the shockwave that pushes other people when your car gets removed about as large as the shockwave that actually pushes people? Right now, the visuel-effect is much smaller than the physics-effect. So you don't see the
dust hitting you, but you still get pushed, it felt "wrong" at first.

Otherwise no negative criticism. I simply loved the game.