Hehe, yeah - the physics in Trackmania are quite funcy. GTA:SA has magnitudes more realistic physics, but then again, Trackmania doesn't really try to be very realistic.
It's a shame really, because it means Trackmania skill doesn't really transfer that well to other racing games, like MTA:Race. I can see how playing both can mess with how well you do. Anyways, sad to see you go. You're welcome back any time though.