The XJ220, Countach, Veyron 16.4, CTR Yellow Bird, Stratos, Supra RZ, Corvette C1, C2, C4, Ford GT40 Race Car would all like a word with you
Like I said the Veyron is an exception, I'd agree with the Countach as well since it was only featured in GTPSP, not any console GTs.
XJ220-I love Jaguar, my favourite brand so I'm bias when I'd say I'd like this premium, but still want to see more cars before seeing cars upgraded to premium. Like the XJR-15 which was in older GTs. Or how about the new XJs or the X-Drive would be fun to see too.
Yellow Bird-Why? Get new RUFs before making it premium.
Stratos-I like the Stratos but I'd say there's a number of cars far before this that would need to be made premium.
Supra RZ-Again why? I know the Supra is popular but again there are so many cars that need to be premium before this and still a number of cars that need to be added before cars be made premium, been saying that all along.
C1-No
C2-No
C4-No, to all those because again (this deserves bold red text)
why? You try convincing me that those cars out of all the ones you mentioned, are cars that need to be premium?! Those must be some personal favourites there, whereas there are cars that DESERVE premium. Like you said the Veyron is one, which needed to be premium at the start, the Countach too. But old corvettes?! No.
GT40 Race Car-Ok I love this car, and if they wanted to make this premium here's how I'd do it. Make a Ford DLC pack and include maybe the following cars,
Ford GR-1
Ford Shelby Mustang 2013
Ford Mustang Saleen
Ford Mustang GT-R Concept
Ford GT40 Road Car
and in that make the GT40 premium. Now that's all unlikely but that's what I'd do. Doesn't have to be those specific cars either but do something like that. Maybe just release the GT40 Road car and make the Race Car premium with that. Also there is a premium GT40 in GT5.