This thread had me thinking about the USCI and how the GTV cars stacked up against each other. So I parsed the results just for fun. As I've already said fun and seat time are more imporatant to me than all out competition. There are 32 (out of 84 total) pre 1990 cars listed on the USCI results page. Of those 17 managed to score points.
Excluding the road ralley and design & engineering here is how those 17 cars stack up against eachother. Note I didn't separate the GTL cars from the pre 1990 cars so this includes both.