http://www.cthreeracing.com (was featured in Oct '01 Sport Compact Car)
http://www.corolla-racing.com (free stickers! other cool shit too)
http://clubs.yahoo.com/clubs/corollacustomz (Toronto-based Corolla club, finally found a Corolla-specific club in my area!)

You forgot the best ones!!!

http://www.club4ag.com
http://www.geocities.com/dori_kaze

Thanks. Great links.