So I decided to build rover, for understanding of wheel mechanics. I created simple car, just four wheels and a sit. The problem begins on the lanchpad (or runaway, I tested both) when I press W - car accelerate as it suppose to. But when I press S acceleration begins to increase till it reach max speed. Even from the first step, if I press S car just don't go backwards. I've already changed keys to numpad, so nothing should interfere with settings. Does somebody know what is wrong?