I think the game could use some smaller 80's and 90's era American cars. There's plenty of big American brutes in the game and it would be cool to see some smaller, more modern ones.
Chrysler New Yorker - A clapped-out New Yorker with the classic rear-end sag would be a good C-class contender.
Foxbody Mustang - Not even a V8 or anything, 90 hp four-banger all the way.
Ford Falcon & Holden Commodore - Not American, but these are go-to cars for derbies in Australia and New Zealand. Bonus points for ute versions. Might need some creative visual upgrades to distract from the overall boring looks though.
How about a Bricklin SV1 ? image from 24 hours of lemons, 1970's v8 powered sports car, about 3000 built before the company went under, change the doors too a part of the rollcage so the large roof cage or roof bar can be installed.
Perhaps performance wise set it just around the wildking on stiff suspension & bit less wheelspin on 3rd gear.
And perhaps a Pontiac Bonneville with donk styling ?
Make it squat off the line like the killerbee with the performance of the gatecrasher and have the handling done so it doesn't tip over easily.
Corvair with a jaguar V6 in the front from 24 hours of lemons, make it similar too the hotshot performance wise, maybe like 20 hp or so more.
Also a car like this would be fun, That is a Toyota MR2 with a vw van body somewhat stylized & shortened added on it.
A lowered minitruck of some sort like this chevy s10 i think it said it was ?
Toyota Hilux body dropped onto a mercedes diesel as another example.
A Mini Moke perhaps ? can make it a fwd special that has like 2.5 durability & 160 km/h top speed as A class car
Lemons images ofc.
What an original Mini Moke looks like.
Nash Airflyte 1940's bathtub with a V8 & can probably give it the performance of the Rammer & it wouldn't be that out of place.
Peugeot 404 rwd, wobbly suspension with low power (original motor makes like 68 hp.)
Yeah, those Nash's tended to be unibody framed. The driver might have figured that would help. The old Hudsons were also. Earliest Nash's tended to be a little lighter, though.
"Crumple zone? That's in the car I run into!"
Early NASCAR had a few Nash drivers. They sort of got screwed because they weren't allowed to use all of the common upgrade parts. They also had a slight tendency to overheat. There are some neat videos of them bouncing over bumps and ruts at the old Daytona Beach track. One of the top pre-NASCAR drivers was a Nash driver.
Later Chryslers got used for demo derbies for the same reason.
If you want freaky looking cars, old Czech Tatras got used for racing.