put your car in neutral and turn off your engine, see what happens. You can still steer and brake, but for a sharp turn or down an incline you would be surprised how hard it is without servo steering and the vacuum servo.
Imagine my surprise when I pulled a headless debootstrap chroot upgrade of a squeeze debian box that did not come up after rebooting.
I had to order a remote KMS session to figure out what went wrong: debian did not include the pretty common realtek-firmware and I was not able to apt-get it without a network interface. Luckily I was able to use it from a the previous installation.