I have a nephew that has a old K5 blazer that the doors must be 100 lb. and are slaging,I,m sure. And he slamed the door on my 46 COE wrecker so hard a thought all the glass would be cracked.I had to say (don,t do that). The other thing I did'nt like is when someone was driving in the next lane trying to take a picture of my truck with a cell phone!