I have crash tested it, all us irrisposible young dickheads had no seatbelts
Consider this .
Many years ago my mate was driving a HT wagon at about 65 MPH when the LHF ball joint collapsed on a right hand band . The car went into a spoon drain and hit a gum tree about six feet in diameter at the base.
The passenger sitting in the middle of the back seat had no seat belt on, he went through the windscreen , hit the tree and ended up back inside the car with his right right leg caught between the seat ( that had fallen forward ) and the rear compartment / dog box . because of the flex of the car when it came to a stop his leg was squashed in the gap. The fireman actually cut the car in half to get him out.
He has a slight limp an got over 280 stitches in his head.
Rectum f'n nearly killed I'm
If Iwas going to have loved ones or mates in the rear seat i'd lock it down
Brad.