The picture shows the most sophisticated algorithm I came up with. It makes only one side of the wall work, but at least it does what Its supposed to do until you collide with two or more walls, when It breaks absolutely.
I have also tried Push out solids at the opposite angle, in case of which the car always stops on collision and can never slide along the wall.
I have tried Push out solids at the nearest angle, in case of which it oftentimes speeds up the car on collision or on rotation.
The question is - is there a single way to make SOLID blocks actually SOLID, so that they would be unpassable under ANY circumstances. (Must work with Custom Movement though)