Out of these three, the M3(why the heck it took 21 years to finally be in the game?). Brought back memories from when my brother had his E30 M3. It's racing pedigree, is enough to tell the story of this icon.
These cars, mainly by discussion, are probably the most significant in this website.
Yes, the M3 and Supra are at the top of the Suggestions. I guess nearly 2000 votes between the two, are minor compared to the actual members on this site. It's that the 996 was, of course, not usable to majority GT players. Also that Kaz has/had one and this one in game, uses(I believe) his car's default color. That's a big treat to finally have it in a GT.
The Supra is that legend. Not even about FF movies. It's been in every GT from GT1. Over 1000hp tuning, the JGTC and Super GT500 models, the racing modifications. Why it took so long to become Super Premium? Doesn't matter. It's been done and we can enjoy the details.
I have a few others that made me happy(300SEL, GR.4 Supra, GR.4 Mustang, believe it or not- GR.4 Atenza). But. I believe these three sum up this era of GT(though Kaz says GTSport begins the next era) before we move to PS5.