I've been trying this recently. You can sort-of fake it up. I ended up using two actors stuck together with a joint, one dragging the other around. Problem is, you can't use friction from a top-down perspective because it only works on the collisions between different shapes (think side-on view rather than top-down). You can alter the weights of actors, but not much else would influence the handling for a top-down perspective. I'd love to know if anybody else has had any success with this though.