The "grabber" could not open the rear car door so it may have been locked? At least, it appears to me by the vid that he did try to open that door when he got out of the car. So, possibly the driver reached back and unlocked it, and maybe opened it. But that seems not as plausible to me as there being a passenger in the back seat, maybe one who was seated behind the driver and needed a few seconds to scoot over. Maybe those poor slobs didn't even know that rear door was locked initially!! So, while obviously not the sharpest tools in the shed, it seems they had planned to grab someone given they had a towel (likely with some chemical on it) handy. Not something most motorists just drive around with, ya know.