Another place to go for add-ons would be
http://www.nogripracing.comSome other sites that I go to for rFactor mods:
http://www.enduracers.com(An endurance racing mod - one of the best I've ever driven)
http://www.drivingitalia.net/forum/inde ... &showcat=2(Has a lot of add-ons including a really cool HUD that gives you a ton of information while your driving)
http://39data.web.fc2.com (Links are at the bottom left of this page. Note: many of the links may be dead because they went to megaupload pages.)
https://shiftstreet.wordpress.com(The Holy Trail - THE STREET SHIFT MOD!!! You can drive all kinds of street this one so you're no longer limited to racing on a track. Take these out on some of the bigger road courses or street courses you can use in rFactor and you will not be disappointed!)
http://sstrcaraddons.neocities.org(Additional add-on cars for the Street Shift mod.
http://www.wcp-series.com(If you are into Formula One this is the place to go.)
It's a pity that VHR isn't up anymore because that's the place to go for what I think was the best NASCAR SIM out there. I think I still have the installation files for VHR 10-14 however, and if I do I can put them up and provide links for them. Yeah, I know a lot of people accused Dave of stealing a lot of the stuff that went into that mod, but truthfully a lot of guys stole stuff to make NASCAR mods back then and there was a lot of jealousy and trolling over on rFactorcentral. Which in the end was probably why modding for stockcars died over there finally. Waaaaaaay too much drama for a driving SIM.
Anyway, off the top of my head that's what I can come up with. There are also paintjobs for cars you can download at rFc - yes, including some of mine. So take a good look over there and see whatever tickles your fancy.
Also keep in mind that rFactor 2 is now out - however the mod community hasn't quite caught up with it yet as it is still in the beta stage if I have this right. I'm not sure if there is a full release of that yet - I could be wrong. But the newer version includes new features like engine wear, changing track conditions and tire wear, so it forces you to be a driver who cares more for the vehicle in the end. It's based off of the rFactor Pro simulator that they provided to racing teams for use in working on setups and race prep.