We already do have diesels in the game - though only a couple of road cars at the moment (Mazda Atenza and Demio XD models), and the three diesel LMP1s from Audi and Peugeot.
Previously there was also the BMW 120d, which was the first diesel in the series' history in the Virtual Drive demo a few months before GT4.
I think a Fox Body Mustang would be a cool addition. Taking a look at the Gran Tourismo Wiki page, a Fox Body has never been in any version of the game. Considering how this generation of the car was a part of DTM racing history, I think it is deserving of being in the game.
Now that we have Opel back in GT, I’d love to see PD add the 1982 Ascona 400 Group 4 Rally Car which gave Walter Röhrl his second WRC driver’s championship in the first ever year of Group B rally racing, beating out the monstrous Audi Quattro in its debut season along with rally legends Michèle Mouton and Hannu Mikkola.
PD has done a very good job in doing the 80s turbo hatchback segment and indeed the European economy car segment justice so this has a great field of rivals already in game, and it would be great to see another Abarth get added into the game as well. A good example of 80s style and quirkiness that competed against cars like the Golf, Escort, and Renault 14, this would add to a good selection of Italian turbo boxes already in the game like the A112 Abarth, and the Delta Integrale.
Maserati MC12 (both 04 and 05 models, 05 model is shorter, the GT1 race car could be added so Maserati could be eligible to Manufacturers Cup if the GranTurismo GT4 is also added)
