I had this idea that was so out there, even I'd call it absurd. It could be something for a future Gran Turismo title, but I could see it being a part of any racing game that uses licensed cars. It'd basically be a "Gr.F" for various Formula 1 cars, ranging from the late-80s to the near-present. I know it's absurd with all the changes in technology, but I'd also say that's what BoP is for. (Personally, I'd just begin with making the power and weight roughly the same for every vehicle, and then make slight adjustments, especially for cars that have ERS, DRS, and so on.)
But the biggest reason I think it could be neat, is because of the sheer variety of automakers that could be represented in this group - and especially if one counts engine suppliers, just like how the McLaren F1 GTR was listed as a BMW in Gran Turismo 4. Heck, even Indycar/CART could be a part of this madness. So between the timeframe I gave for F1 cars, and the idea of including Indycar/CART in this "Gr.F," this would include the following automakers:
Alfa Romeo
Brabham*
BMW
Caterham
Chevrolet (Indycar)
Dallara*
Ferrari
Fittipaldi Automotive**
Ford
Honda
Jaguar
Lamborghini
Lotus
Mercedes-Benz
McLaren
Red Bull (I think it ought to be its own brand in Gran Turismo, considering the Red Bull cars.)
Renault
Spyker
Subaru
Toyota
Venturi
* It'd be especially nice if we saw the road cars from these companies, like the newer Dallara Stradale and Brabham BT62.
** Might be stretching the timeframe a bit far, but even if it were added as a Gr.X car, it'd be nice to give the EF7 a historic companion.
There could even be a historic formula class, meant for racers of the 50s and 60s, and would allow representation of the following automakers:
Alfa Romeo
Aston Martin
Bugatti
De Tomaso
Ferrari
Gordini
Honda
McLaren
Mercedes-Benz
Lancia
Lotus
Porsche
Granted, I think this would all be better for one of the F1-licensed games than GT, but I think it's still fun to think about how far you can push the inclusivity of a group. For GT, I'd be perfectly content with a series of Gr.X cars meant for one-makes, but also typically allowing two identical vehicles (say, from the same season of the same racing series, like the Dallara SF19) to often be permitted alongside each other, rather than one at a time. I can't imagine licensing being too easy for F1/GP2/F3/etc. cars, either, but then again, I wonder what's left to the FIA's discretion, rather than Formula One as its own entity. Could be that the FIA would be largely on-board with the licensing of F1 cars, but it's really up to the discretion of Formula One's people, y'know?
I'd really like the F2007, F10, 98T and W08 to show up in the next game, maybe even one of the F1 cars that were used as a basis for the Gran Turismo 3 cars, like the MP4. There could be Fraga's F3 car sponsored by GT, as well as the other Senna cars, and ideally, the Mercedes VGT LH Edition will make the jump.