You could be right about the Renault 21 Matt, must dig out the photos from that year! Was going on memory and I was well and truly on the "beer" side of the fence that year, and was probably already semi-comatose by then - the whole of 1990 is a blur and all the photos generally related to drinking exploits in those days and various things going up my nose, but definitely remember one of a severely damaged car (but not burnt out) in the paddock somewhere between MB campsite and the startline terracing.
Just checked out my Autospurt from that year and you are right!! It was a Renault 21 and the driver was Wolfgang Schutz and all the comic says is that he "was removed and taken to hospital, and, although he suffered no external injuries, was still unconscious on Monday".
Maybe it was some kind of saloon race as I'm faily sure the wreck I saw was a 309 - but then again .............