Originally Posted by mattd2
Yeah be careful - my old man was "slightly taped" on the rear bumber by another guy a while ago. Both cars looked like nothing had happened so they shook hands and just aprted ways, nothing more. Over the next few days the bumber actually pulled itself back - seems like the supports had bent but the plastic was stiff enough to push back so that it looked fine but over a few days the plastic slowly creeped into a buckled state. Not much but would of probably meant a new bumper, supports, etc = $2000 for a pro to do it. I got out the heat gun and hammer, bashed the supports straight and reworked the bumper - didn't look mint but good enough that you wouldn't notice.
Be careful with bumper work. Once the low impact bumpers do their jobs they wont work as well next time. Much like motorcycle helmets they are one time use safety features.