Actually I wouldn't want to release ''physics'' for existing cars, because the whole problem with rFactor is that there are too many mods and too many versions of mods and tracks. Online is a nightmare. If I'd release something new for an existing mod, the online situation would get even more nightmareish as half use my version and the other half the original version.
Plus, since making my own cars, (I really dislike 'mods' and 'physics'.. lets say cars..
) I'd hate it for some wiseguy to spend 20 mins changing the grip levels or engine power and releasing it as an 'upgrade', when I've spend 100+ hours trying to get where I am.
If I don't want people to change my cars (there is no way I can stop them though..) I certainly shouldn't be changing other peoples cars and releasing the files!
My opinion is, if you want to 'mod', go make your own mod, not tweak someone elses. And I might actually be involved soonish with a car that laps fast at Le Mans..