I use these. I keep two sets in the trunk.
If I'm only parking for an hour or less I just park a long walk away. the average idiot who is likely to ding a door next to him won't park that far. I also avoid parking at the bottom of a sloping parking lot where a shopping kart might roll towards me, park at the top of the hill.
And always look for the parking spot where someone can only park on one side of you if far away parking is not available.
door shox
