Ever come back to your car to find that someone dinged it while you were away? You might have a better chance at catching the culprit in the future. Germany's Hella is developing a smart body panel that uses a grid of foil-like pressure-sensitive electronic sensors (plus special algorithms) to detect when someone dents or scratches your vehicle. It can even tie into onboard cameras and GPS to both record where the car was and get some video evidence, so you can show that someone else's botched parking job wrecked your ride. Of course, this might also work against you. Insurers could use dent alerts to hike your rates on the fly, and rental agencies could penalize you for damage before you've even returned to the lot.