I just got off the phone with a guy in KY that has a warehouse full of used E30 parts. I just bought a tail light assembly from him for $10. Tell him you race E30’s. Tim’s contact info:
TimandCathy59@yahoo.com (this is untested)
Home 859-881-5349
Cell 859-270-3333
To my uneducated ear, he seems to know everything there is to know about E30 parts. Note also that he is interested in some wheels that will fit an E24.