A "supercar" is a noun to me, not an adjective. It's not something you define and decide to later change or "downgrade" because performance standards have risen so high. The MKIV was and still is just a sports car. If Toyota had dropped the MKIV in 1980 - at the same MSRP it was tagged in the 90's - it would have a supercar title. But in 1993 there were Bugatti EB110s, Jaguar XJ220s, Lamborghini Diablos, Ferrari F50s, McLaren F1s...some of the most influential vehicles of all time.
Tell me with a straight face that if you and a buddy see a Diablo cruise out to CC&C and park next to a MKIV Supra, you would say "hey, grab the camera I want a picture of these two supercars next to each other!" *fart noises*
What if said imaginary Diablo were parked next to a new Aventador. How would that go? "hey, grab the camera I want a picture of these two supercars next to each other!"
Any normal person that overhears you: "ughhh. Excuse you, the Diablo hasn't been a supercar since the mid 90's, by today's performance standards it's a "sports car" at best. ACTUALLY, another little known fact, a new BRZ holds higher lateral g..." *punched in the face/kicked in the sack/sweet whispers of unconscious farts*
I saw Kerry try to defend himself with hypercar somewhere too. I didn't hear that term used until recently to describe cars like the P1, Spyder and LaFerrari. I certainly never heard it in the 90s or 25 years to follow.