Poltergeist in my 2005 97X
 

As I am driving auto locking goes off and on. Service brake appears on dashboard info. ABS light and warning bells go off. Brake pedal becomes spongy. Tach neede, speedometer needle, and gear selection indicator slide up and down or back and forth. It can run for hours in a normal state and then if it acts up that can last for a long while. No definite pattern.
It’s been in several shops and no one can diagnose the issue. It seems that GM abandoned the Saab diagnostics and the GM diagnostics will not recognize the VIN.
I reside in central Vermont and have contacted several Saab techs listed on Google with no success and no referrals. My vehicle is in excellent condition and I would like to keep it, but if I can’t get this resolved I would have to say that it’s totaled.
I would appreciate any and all advice.