Sit back, relax and let your car parallel park itself — without a single scratch or ding to your bumper. That’s what Ford said Tuesday about its new self-parking technology, which it announced will debut as an option on the 2010 Lincoln MKS sedan and the new seven-passenger Lincoln MKT luxury crossover vehicle. The technology uses ultrasonic sensors on the front and rear of the vehicle, combined with electric power steering to angle and guide it into a snug parking space — all with the push of a button.