There are pics of the car in the F5000 Thunder book for comparison...

At least one Barry Singleton's story and there's a story from Jaime Gard as well.

I really don't think it looked like the pics shown, but I'd need to have a look at the pics to decide whether or not it's just the colour or something that's different. It was a very late car in the F5000 era, so it shouldn't have been changed much at all.