As it is visible, 1966 Lincoln Continental has filler cap on the left side. Kjeld and Benny purportedly pumped out fuel from the car while being on its right side.
When the gang unscrews the back plate of the World Bank box, they turn the bolt the wrong way. But maybe the bolt has a left-hand thread.
About 10 minutes and 45 seconds into the movie, we see the character Egon carry luggage down a hallway. It is clear that there is a large mirror or painting at the end of the hallway, in order to create the illusion that the hallway is longer.