That (neighbor's Viper) has to be a 92 or early 93 due to antenna. It has an aftermarket hardtop (not sure which--does not look like Autoform, maybe V-Mania) I have VIN 00002--second one built I bought from the former President of Chrysler (most recently retired Vice Chair of GM). Mine has several odd things on it.
Atomic--that has to be a prototype--we may just disagree on semantics--it was not a "produced" Viper. Windshield etc would not have been legal.
The first 17 or 18 went to company execs, Iaccoca as VIN 00001. I had 2 Gens 1s (92 and 95)--both are a handful. In terms of handling, if you want to experience the opposite of a GT drive a Gen 1 Viper--but really neat cars
My 92 drives like new--though I rarely drive it.