Awesome thread!
Ok, this is my top ten list of Very Rare relatively inexpensive vehicles with a cult following. . I also added there club links.
1 Acura NSX http://www.nsxprime.com/
2 Delorean http://www.deloreanowners.org
3 Chevy SSR http://www.ssrfanatic.com
4 Plymouth Prowler http://www.prowleronline.com
5 Cadillac Allante http://www.allante.com
6 Ford Mustang SVO http://www.svoca.com
7 Buick Grand National http://www.turbobuicks.com
8 Subaru SVX http://www.subarusvx.com
9 Ford SHO http://www.shoclub.com
10 Avanti http://www.theavanti.com