I just did this with a u haul..
Every time that I take my truck in for service ... I walk around it with service writer and my iPhone videoing the walk around. Do this at drop off and pickup.
I also do this when I rent a vehicle too ... especially big trucks. It has saved my azz several times over the years.
Same guy gives me a scratched up truck and I say this is really bad, he says no problem. Next day he is all upset I damaged the u haul. Says it is going to cost me and forgets me bringing it up the day before with him. I guess he did not see me take pictures in his lot with my phone before I left. He remembers the damage after I show him the pics.
I always do a walk around my vehicle before I go in to claim it