Secondly, the shape/type of the car is very important. Batman could have a Mini Cooper, a sleek supercar or a tank.

In the first case he could be stealthy but he wouldnt be able to do anything else.

In the second case he could go fast, maybe run through walls or crash into enemy cars (if its armoured enough) and fire missiles. But as soon as a big obstacle is in the way, or gets under the car, the car will be stranded. Just imagine taking a ferrari on a mountain. It doesnt have the ground clearance.

In the third case, that of the tumbler, you have a huge vehicle, that has a lot of ground clearance, can fire missiles, jump from rooftop to rooftop (thats why it has those big wheels and that shape at the front) and even run fast.
So you see, the vehicle you choose is important.