Anyone ever buy from these guys?

I've personally never dealt with them. But have heard bad things. A quick google search supports that.

Showcars Fiberglass & Steel Bodyparts Unlimited - Totally ripped off
Ripoff Report | showcars-bodyparts.com Complaint Review Internet
Showcars Bodyparts? Anyone? - RX7Club.com - Mazda RX7 Forum
Just so everyone is warned about this company. Showcars Unlimited - Page 6 - Hot Rod Forum : Hotrodders Bulletin Board
Stiffed by Show cars any advice
fiber glass t buckets

And that's only the first half of the page. Some of these are fairly old. But you know what they say. A tiger doesn't change his stripes.