Compact pick-up trucks, Think Ford Ranger, Mazda B series.
Modern Retro Cars: PT CriuserLike, New Beetlelike, New Minilike, HHRLike.
Police Car/Fleet Vehicle Cars: Think 90's Crown Victoria/00's Dodge Charger.
Woodies: Don't forget about the 60's woodie wagon thing in North America!
What about: Top up only convertibles (No I don't mean normal coupes) Something like the modern retro thunderbird, Or the Silvia Varietta.
Limosines (Presidential class, with bulletproof glass!)
Super Utes: Think Ford Excursion/Chevrolet Suburban
Heavy Duty Trucks: F-350/Silverado HD3500 (The truck versions of the above trucks)
Car/Trucks: Dodge Rampage, Chevrolet El Camino, Ford Ranchero, Holden Ute.
Kei Cars! (My favourites!) little 3.495 meters coupes, wagons/tall wagons, sedans and downright silly things. Almost anything by Daihatsu is a good example. Most Japanese (if not all) automakers have at least one they make for their home market.
Also Maybe Big Rigs? I know it's a stretch, but hey car companies tend to make a little of everything. (lol. Ok I admit I'm itching to try a 12 cylinder boxer hybrid diesel in something with the same drag coefficient as a barn, ha)
Long list is long. They're just suggestions, that probably overlap other people's suggestions, please don't flame me. I'm not being demanding. I'd love to pay for an expansion pack anyway. :3