Necessary...

Homologation specials!

Ascari A10 is definitely obscure.

Obscure supercars? That's my fetish

Ahh Mosler.

I raise you an XJ220 S!

Two of my favorites as a kid, from reading the old Sports Car International magazine:

The BEST is the Jag XJ-15

BMW M1

Tramontana R. You are about as likely to see one as your are to witness your own birth. But that only makes them rare - like a Vector. Obscure means there's also a good likelihood that haven't already heard of it - not like a Vector.

how about a Trident Iceni? 660bhp and over 1000lbs/ft. Best of all? Diesel.....

Isdera Silver Arrow C112i

the Venturi Atlantique. For those who loved Gran Turismo 2.

Mercedes-Benz SLR McLaren Stirling Moss

Cerbrera Speed 12

XJR-15

This Merc is on my bucket list to drive before I croak.

The Noble M12. Now, I don't know if it solidly qualifies as a super car, as it isn't in the Aventador/458 Italia/DBS price range. But I love it for its subtlety. There's hardly any badging at all, except for the tiny "Noble" label on the nose, and it looks badass.

Nobel M600

There's something about the Isdera Commendatore 112i that just gets me going. 90's supercar-esque, home made, LeMansey, roof rear-view mirror, was in Need for Speed 2. Man I'd love to see one.