Just come across this game.
Its still in development, but a demo has just been released to test the online playability. In the demo you can race 3 different crs on one track, against online opponents.
The graphics are very similar to live for speed (ie bloody good) and from playing it for a few hours now, id say the driving physics are even better.
The sound is awesome, from the whine of the gears, to the engine note, and the squeaking of the breaks under heavy deceleration.
The full game is going to have a lot of 'customize-abitlity' <-- is that a word?

and the demo already includes lots of car tweaking ability - gear ratios, rev limiters suspension set-ups. From what the menu shows it seem you will be able to upgrade your car, and there is also a 'carreer mode'
This is a proper racing simulation game. No arcade nonesense. You have to think about tires, pit strategy, fuel, all sorts.
I'll have a server set up every now and then so look out for 'topgeartom's [{something or other}]' or anything with JW in the name.
The demo is available for download here:
http://www.gamershell.com/download_7496.shtml
(choose the location nearest you)
and here are a few screenshots:
I'll add a few of my own screenshots later - just to show what the game looks like when it is run on a standard computer - with a good framerate.
Let me know what you think 8)