Dig out lots of pictures that show crashed aircraft because they were overloaded and this stress eventually made the aircraft break in flight due to being overloaded of a long period of time.
Cessna stopped putting long range fuel cells on their 172's cause PPL were giving them full fuel & loading all their crap up like they did when they didnt have excess fuel & things like wing spars and the like would one day bend & a wing snaps off cause it had been had that done to it for a long time & one day gave up being overloaded.
I bet you can find a stack of broken & burnt aircraft to highlight your point.
Aircraft that cant stop on a runway for being too heavy , helicopters the repeatedly have to do running take offs to get ETL to get some fat folk that claim they weigh less, or Loadmasters that under estimate weights of the load so that more can go in.
Ahh she'll be right , this old girl can carry more weight than they say , thats just a safety marging they put it, trust me I have been doing this of years..........
Something like that, I bet NTSB reports are easy enough to filter , just the pictures you really need to bring it all home to folks.
HF
ooh ahh no I cant really help directly , just with suggestions though
