Correct, thats why its a shame the front and rear ride height does not affect downforce. even with a bottom not completly flat, lifting the nose will still guarantee a take off with the bf1,fo8,fox and the gtr' s, because the bottom is always near flat, good enough at high speeds with nose up to get cars into the air. Thats also why all cars nowadays are setup with nose down, including normal road-cars. Every car suffers from this aerodynamic effect, because indeed the entire car can be described as a giant wing. Also you get ground-effect from low ride heights; allthough for low race-classes and road-going cars this effects are minimal but it is there.
I hope in the next patch aero effect of ride height will be present, it will mean the end of all current setups and a big move to more realistic setups, which will be all as low as possible(for faster race-classes) because of the aerodynamics.
Anyway on topic
I like the idea of better textures on bottom of the cars, gives just a bit better feel and look to lfs .
Don't tell me, do you mean the difuser? And racing cars still have pretty flat underbodies. At least the LMPs do (And the CLK-GTRs were LMPs). They on the other hand have 2 difusers, one ebhind the front and one behind the rear axle.
+1, it would add realism if you happen to roll it and would look better than having the big dark space under the car.
For this to work though you would need real looking suspension parts that are joined to the wheels so it matches up, as a realistic bottom of the car with real looking floorpans, exhaust, prop shaft etc, would look strange with the wheels just floating there, not joined to the car.