Thank you! I figure anything under three minutes is a decent time, especially if that was your first try.
The cars do collide with one another so you can shunt opponents around to an extent, but not yet having got four players together online I can't be sure exactly how much of an impact it'll have on the game when you get a real pile-up. My guess is that collisions will generally do more harm than good to everyone involved so the optimum strategy is probably to get out in front as quickly as possible and try not to get blocked into a corner by someone who's also frantically trying to spin their car in the right direction.
That said, you may be able to block an opponent by hogging the left side of the track, then steering right if they try to get around you that way: once you're both scraping the right-hand barrier, they can't realistically overtake.