Since apparently we're now getting Alfa Romeos, how about two early-2000s models that were quite popular in Japan, like...
the Alfa 147 GTA, which could work either as a Retro Hot Hatch or as a plain Hot Hatch? Or perhaps the
Alfa 156 GTA, which would give Alfanatics a Retro Super Saloon that's less, well, retro than the 155 Q4?
I know, I know: neither car's in the Alfa Museum's catalogue. Still: Alfa probably still has the CAD files for both cars somewhere, and the Busso 3.2 V6 should be easy enough to source for audio recordings...
Honestly I'd prefer improvements in how the cars are used (assignment to divisions, the number of performances classes, meta tunes, etc...) over new cars. The car list is already excellent.
That being said, please add:
luxury saloons like 7 series, S classes, Lexus LS and of course the Toyota Century
a few of the most common regular cars (non-sporty) in Japan