Please get off of your cell phone when you are in a parking lot
A woman backs into my wife's Prius while she is in a parking lot and the lady is on her phone. Look at our Prius's bumper. I saw that some people had kind-of fixed a bumper with their hair dryer. So I thought what would happen with a real heat gun? I know that plastic has a memory and wants to be back in shape. I also know that heat can damage paint. What should I do?

I went to the local home projects store and bought a heat gun. This one had multiple heat settings so I thought that would be perfect. It cost me about $35. Next I went on-line and found a site where someone had the instructions for removing a Prius bumper. I followed them. It required a philips screw driver. This was before I had my cool plastic tools (see my article on the tools for a Mercedes 450SL vent removal) Because I did not have the cool plastic tools I had to buy new plastic bumper connectors from Toyota. They came in a pack of ten and I needed about 7.
When I got the bumper off there was a black plastic bumper holder that was broken so I ordered one of those as well. You can see it re-installed in the photo above. Luckily there was no body damage and the Styrofoam was not affected. If your Styrofoam is smashed even a little you want to replace it for safety.
Part of the reason I took the bumper off was so that when I heated it I could do so from the inside. This made it easier not to overheat the paint. As I heated the bumper it started to move. I also applied some pressure using gloves to keep my hands safe. I kind of kneaded it and pushed it. Then some more heat and some more kneading. I took my time and made sure I did not burn myself. I kept heating and shaping until it looked just right. Probably about 30 to 40 minutes.
As you can see the heat gun worked! I took my time and pressed and shaped it from the inside. Next I used some rubbing compound to remove some black scuffs. Then I used a little touch up paint. If you were to look at it today you would have to have the damage pointed out to you for you to see it. It was definitely worth the $35 for the heat gun. If you do the same please remember that I am simply sharing what I did and your results could be completely different. Happy bumper repair and when you are in a parking lot stay off of your cell phone!