I was at a weld shop our company uses out in the country - and this guy is good, Code certified even for nuclear stuff - and I saw some 1/4" wall, 4" struct tube topped by an equally hefty 6" piece, and I said "Charlie, is that a mailbox?" He replied in the affirmative, said a friend of his was sick of replacing mailboxes. We had a good laugh imagining some punk busting the back window out of his car on the bounce-back, with his hands stinging clear up to his elbows, screaming in pain... But I like this solution. Whoever made that dent on the right side was one surprised individual!