maybe this will help y'all out.
I went to my provider, statefarm a while ago and was getting some quotes and here's what ai learned. All non M E34's, E36's, and E30's have the exact same rate. and E36 M3 was like an extra 110 dollars for me as was an E30.
From what i gather, statefarm see's these car not as older high quality high performance sports cars but rather just as being old and they think that means slow. I also at one point got a quote for a 65 mustang fastback that was in the antique car dealer's window and it was like 35$ a month listed as a daily driver.