some less common beauties:
(starting with prototypes)
Lancia LC12
Picchio SR2
Lister LMP-900
Dome S-101
MG LMP 675
Cadillac Northstar LMP
Dallara GC21 (yes, a reconverted F3..)
Martini MK64 Peugeot
MazdaRX 792 P
The Mazda is so beautiful I could cry for hours