Get Your Kicks on Route 666 - S10-E2
Revealing mistake: When the guys are stranded you can tell the background is just a backdrop as the scene is not perfectly flat - there are some wrinkles in it. (00:13:05)
Get Your Kicks on Route 666 - S10-E2
Visible crew/equipment: The edge of the set can be seen after Norm drives up in the golf cart. (00:22:30)
Get Your Kicks on Route 666 - S10-E2
Continuity mistake: When Frasier is sitting at the bar talking about the trip he is going to take, Cliff walks over and sits down. There is a beer sitting in front of him - he pushes it forward and Sam moves it. The shot changes and the beer is back where Cliff had first moved it, and he is holding his own beer. For the rest of the scene his beer keeps appearing and disappearing while the other one keeps changing position.
Answer: Here is the source of the "WE WIN" photo: http://www.oldnycphotos.com/nyny587ac.html Brooklyn, of all places.