[drunken monkey]

and who says a supercar cannot be an exotic car?
exotic is something out of the ordinary.
a lotus exige isn't a supercar?
a tuscan s isn't a supercar?
a carrera gt isn't a supercar?

on the other hand,
is an ariel atom a supercar?
is caterham superlight R500 a supercar?
a noble m12 gto isn't but a m400 is?

what you have listed are more or less race cars (which can also be supercars i guess)....
in my opinion, you have a skewed view of how to class cars (also i would say rather 'pointless')
following your rationale, a stock car with a hyped up engine can be classed as a supercar cos it is
i) 0-60 in sub 3.whatever.
ii) super rare (cos it'll be the only exact example of it in the world)

i think a supercar is one that sets out to do something 'more' than the thing that came before.

numbers do not figure into the whole supercar equation because that is dependent on the time period from which the car comes from,
not to mention that the 0-60 is dependent on the gear ratios.....
by looking at pure numbers you are totally ignoring the achievements of things that have past.

i think a supercar is one that changes your idea of what a car is or what a car can do.

i think the humble nsx is a supercar because it showed the whole world that you can build a car almost entirely out of aluminium and what a difference a good set up can make.

the modern V8 ferraris and 911s are supercars because they have an almost race spec engine, using all of the latest technology in both construction and materials and techniques.

i guess you can say that what makes a supercar is it's focus.
the supercar has an aim to be fast that is true
but
i think more importantly, it is one that doesn't care about the real world and just does what it sets out to do.
but then even, why can't super fast cars be super comfortable too?

there is no definition of a supercar.
it is super if you think it is.

i have a passion for cerberas and tuscans and most of all ferrari 365 boxers.
none of them can do a 0-60 in less than 4 secs.
none of them are particulary rare (except the 25-30 year old ferrari...)
and they don't cost much.
but they are supercars.