Well, I'll throw in my 2 cents since no one else seems to be
I haven't had to get mine smogged yet, but the word I've got around the Bay Area is to get in touch with Valaya Racing in San Jose (
Valaya Racing). They have a good connection with a smog place in that area that works with Vipers. Especially those that may not be stock. Worth a quick call to see what they recommend. If you do, let me know how it works out.
By the way, was it your red GTS I saw on Monday in the Safeway shopping center on Ygnacio/Clayton Rd. in Clayton? Just curious, I've never seen the car in the area and I'm pretty sure it was a '98.