I've seen videos that when engines in cars leans, it also affects the car to lean aswell, even i tried to my mom's car do you think this is should be added, or not?
Most noticeable in either slow mo when free revving the engines in neutral. Or if you set gravity positive, float upwards a bit, set it to zero, reload the car. As you rev the car will spin on the engines axis.
In a longitudinal engine layout it will very noticeably lean when revving it IRL. In BeamNG you can see it lean a bit.
This effect would be more noticeable in a rotary engine, where all of the power comes from the spin. At least it's apparent on my '79 Rx7.
Longitudinal vs transverse makes all the difference. In my mom's Rav (Transverse I4) I really don't notice much movement when revving but in my sister's old Passat (Longitudinal V6) it was very noticeable when revving it.
Thats simply a case of the rotation being in a different axis making it appear less noticeable. In my car IRL it is best noticed by simply opening the hood and watching the engine twist on its mounts, it doesnt have the HP to do much more than that. Newtons 3rd law cannot be avoided.