[Armin]

Some of the vehicles in Basic Set are noted as TL:8 (SUV and Luxury Car, for example), so I'm not sure what you're seeing that's a problem; obviously some of the data agrees with you.

From what I see, no cars are tagged with the actual tech level, so all the TL notes are simply in the name of the vehicle itself. So if your car says it's name is Audi R8 Spyder 4.2 Quattro (TL7;) then the (TL7;) part is the name extension. Just edit it like any other name.

If you want to change the data file, in addition to changing the description of the vehicle to include TL:8, you might want to change the techlvl() tag to techlvl(8). That won't affect anything inside GCA, but IIRC is used for marking in what TL things became available so that they can be removed by the data file that exists for that purpose.