well... if you have a longer car that is flatter it will have lift which lowers speed or it will lift off the ground.
Not as much as the shape of the car but different finishes do affect drag.
a cube
The shape of a car can impact its speed by affecting factors such as aerodynamics. A more streamlined shape reduces air resistance, allowing the car to move more efficiently through the air and potentially reach higher speeds. Conversely, a boxy or less aerodynamic shape can create more drag, limiting the car's maximum speed.
A small skinny car is best. you can even cut out peices of wood in the shape to make it lighter.
Bugatti chiron
Oh, dude, it's like this - the shape of a car can totally impact its speed because of aerodynamics. A sleek, streamlined shape reduces drag, helping the car cut through the air faster. So, if you wanna go zoom zoom, you better make sure your car is as smooth as a baby's bottom.
the blue
viper
Need For Speed : Hot Pursuit is recently the best car game.
MERCEDIES
If you have a big truck instead of a little car such as my dads Honda crx, the shape of it creates wind resistance so your engine has to work harder to fight the wing. Basically you get less gas milage not that trucks get good gas milage anyways.
the shape of the car is vital when designing because if you want a high speed car then it has to be aerodynamic this makes it easier for the air to go around the car and stops it from having drag drag is the force of the air that is pushing on a car if you want a fast car you need less drag