I never removed them for two reasons:
1) car was buffed really pretty before I bought it, so who knows what the original owner did or didn't do to the car's paint. I didn't want to remove the ding guards and find faded paint that required a detail shop
2) Door dings are there because 50% of people are too stupid to look before they slam open their door. I would know I've gotten 2 dings + the two that came with the Tour.