Protect against dents from door key

DebsCamper

Hi there!  I was wondering if anyone has any good tips on how to protect the side of the van from dents from the door key?  On our Lunar the door key is bigger than the gap provided & we've gained a baby dent already.  Would appreciate anyone's suggestions about how we could put a bit of protection in place.  I'm thinking a piece of sponge (maybe key hole shaped to be ironic) but not sure how to stick it to the van.  Any other suggestions would be welcome