But, people already create 4-door '87 GTIs. That to me, seems even worse than using a 94 (1.8) Miata tub for what will be raced as a 91 (1.6) car
[/b]
i don't know about the VW stuff, but here's a specific example of what i'm talking about.....

if i swap a 1.8L into my 1.6L tub (or do i have to swap my 1.8 tub with a 1.6? whatever ) i end up with smaller/lighter (but still good enough) brake rotors at each corner. this creates an advantage for the 'hybrid' car that didn't exist when the respective models were classed. find some specific make/model combination that you can find just the right advantage and you may have yourself an overdog.

or am i not reading this rule change right?