I would imagine that you might be ok with Saxo's especially the 8v ones whichever they are.
I would avoid Civic Type Rs, Clio 172s etc. Renault 5 GTturbos, RS turbos. And definitley G40s should you be lucky enough to see one.
Stick to racing other Gti's and XR2is, XR3is, AXGTs etc etc.
Oh yeah.... You can race just about ANY mk4 Golf Gti and win but leave them funny R32 thingies well alone.