I'd be totally down for more kei cars, especially the following:
Daihatsu Copen GR Sport
Daihatsu Midget II
Mazda Autozam AZ-1
Suzuki Alto Works Suzuki Sport Limited
Subaru R-2
As another note, since AMG is its own brand in GT7, I think we really ought to get the AMG Galant.
1. G80 M3
2. G80 M4
3. F80 M3
4. Cadillac V Blackwings (All of them)
I'd be fine with just the G80 M4 and the CT5-V Blackwing of those. As for any M5, I'd especially like the E60 with the V10.
EDIT: I really think we could use more French cars in general, such as the following models - an asterisk marks models returning from previous GT games.
Alpine A310*
Alpine A242 (Gr.1)
Bugatti Bolide
Bugatti EB110 SS
Bugatti Type 37
Bugatti Type 57
Citroen 2CV*
Citroen SM
Citroen C4 Coupe*
Citroen BX GTi
Peugeot 106 S16*
Peugeot 205 T16*
Peugeot 207 GTi*
Peugeot 905* (Gr.1)
Peugeot 9X8 (Gr.1)
Renault Espace F1*
Renualt R5 Turbo Rallye* (Gr.B)
Renault Twingo (1st-gen)
EDIT2: I wanna mention some stuff about Gr.1, specifically what I
don't think would be a good fit. I'm talkin' about LMP2 machines, or IMSA GTP racers that didn't have functioning headlamps. But I think it gets more complex when you involve Group C cars, as the oldest ones we have are from '88. So I think the Group C racers from Dome, Lancia, McLaren, and Lamborghini might be too old, as would the Porsche 962's slightly older sibling, the 956. The SARD MC86X might also be cutting it a bit too close, as would the TOM'S 86C. The Ford C100 is
definitely too old.
Fortunately, this still leaves us with some potential additions to the other Group C racers:
Alfa Romeo SE048SP '90
Aston Martin AMR1 '89
Peugeot 905B '92
Toyota TS010 '92
Now of these particular four, I'd love to see the 905B return from prior games, and I think the TS010 would actually be preferable to the return of the 88C-V, if only to show where the "TS" program all began. Meanwhile, although the AMR1 competed in the LM24 in '89, I think I'd rather wait for the LMH-spec Valkyrie as far as a potential Aston Martin Gr.1 car goes. Meanwhile, the Alfa Romeo didn't race at all, but I don't think the Jaguar XJ13 hit the track, either, so why not throw it in anyway? But I'd really prefer the Peugeot and Toyota, first.