These are some of the sites I frequent:

Team NABR, not the place for the weak minded. http://www.teamnabr.com/cgi-bin/ultimatebb.cgi

Ron Shearer, best headers out there: http://www.shearerfab.com/

EVO-M.  http://evolutionm.net/

Glock talk, im here alot. http://glocktalk.com/

S2kI Site for Honda S2000 owners(my winter ride). http://www.s2ki.com/forums/

Nate Silveri www.tpgtuning.com  

Wesley Hess(brakes, headers, other cool stuff) http://www.hesspower.com/contact.html

 Roll bars at http://www.dominationchassis.com/