Wow, this is some excellent work.
After your suggestion a few days ago I had been wondering if I maybe should have started such a therad myself, but you've done a much better job than I ever could, much respect.
I said I would sticky it... so I did.
Yeah, I had discovered Lespittet myself, a pretty amazing collection (most of it pre-2001), and equally amazing it's still around (his NFS3 collection is even bigger)
But yeah, there are no previews and there's no credit to the authors (most zips don't contain a readme) so you have to guess a bit which car you're downloading.
I honestly thought GearfX was gone, guess I bookmarked the wrong url. Quite a relief.
PassatNFS was a site I'd never heard of, thanks for sharing.
Site that seems to have been frozen in the year 1999, still holds several modes and tools for NFS2 (!) and NFS3.ftp://ftp.ea.com/pub/ea/
Official EA ftp that still holds official patchjes for the older games, including the official addon cars. Looking around that server you may also find some official MCO stuff, as well as screenshots and movies (look under patches, misc and movies).http://members.rennlist.com/countach/icedesign.html
A single page with a few tracks and two cars, downloads still work. http://www.jimi-w.de/NFS/nfs.htm
I don't even remember bookmarking this, but to my surprise the downloads still work. I honestly can't remember if the tracks are any good, though, maybe I should try to filter by quality a bit. http://nfstoolbox.suckosaurus.dk/
Home of Viv Wizard and NFS Wizard.
Will add more if I can find them.