Factual error: Why don't the "beer" bottles on the floor of the van fall over? When the cop stops Harry and Lloyd the bottles are all standing perfectly upright and there has not been any spillage on the floor. Bear in mind that before this they had been driving on the verge and stopping and swaying when the cop tells them to pull over. And Harry is only holding 3, and yet 6 appear on the floor.
Factual error: When Lloyd drops Mary off at the airport, he watches her leave and then hits a parked car, inflating the airbag. First, the Cadillac Brougham Lloyd is driving was never available with a driver-side airbag, and secondly airbags are not designed to inflate after such a low-speed impact.