There aren't many FOSS games from that era, are you sure about the name?

Might it be ManiaDrive?

http://maniadrive.raydium.org/index.php?downloads=yes

Or vDrift?

https://vdrift.net

TORCS?

https://sourceforge.net/projects/torcs/

Not the same one; I remember it only had one car (red one, Mitsubishi maybe) and one track. Very much a WIP.

Was it this one? https://sourceforge.net/projects/trigger-rally/

Yup :-) Still in the repo. Got a lot more tracks now too.

I remember this game as well. I wish I could remember the exact name.

What type of racing? Drifting, simulation?