Widest tyre/tire for 1990 80Q?

[elweasel at bellsouth.net]

Yes, I see your point. I could put a meter wide tyre on the audi but it would be a museum piece. No I wish to drive the 80Q. So that means the the tyre needs to clear the suspension and brakes. So I asked again, What is the widest tyre you can fit on a 1990 80Q with Speedline rims, size =15"and still run the car without hitting any part of the car. And the same question on 14" rims.  For example I own a 2006 VW Jetta  and the widest tyres that VW suggest is 235. Some people have been anble to fit 245 but it rubs a little bit. I thought it was a simple question but I guess it was a bit more involved. Thank you for any good answer to my questions.