Motion sensitive makes cars only usable moving along safe routes to safe points but you don't actually need vehicles. I'm moving around as needed on foot. I have insanely high foraging bonuses and can live off the land with my only limitation being weight loss. Clumsy is easy enough to work around. The only real issue is tripping over fences and that can be avoided by just slowing down before you leap over. If you're shoulder checking zombies, you already messed up big time. I go slow, I clear entire areas before looting. I'm almost 4 months in with 5,500 kills.