Ok I'll give in on the online barrier ramming bit, but you only get that on the beginner and intermediate races because the people you play against are... Well, rubbish. In the expert races you rarely get slammed off the track.
If your 500bhp skyline is being whooped by a clio, I'd suggest sorting out your settings! took me days to figure out a decent set up for a s2000, it soo isn't a plug and play game, but get the right settings a cappachino will keep up with a Ferrari.
Also with the download errors, that was sorted months ago.