Episode #2.8 - S2-E8
Factual error: The silver Ford Granada seen in the final episode is a Ghia model, which was not made until 1975.
Episode #2.3 - S2-E3
Factual error: Sam and Gene arrive at a construction site to investigate stolen explosives. There is a green first generation Range Rover parked on the site. The Range Rover has its driver side (right side) side view mirror mounted on the door. In 1973 Range Rovers had side view mirrors mounted on the front end of the front wing (fender), not the door. The mirror was not mounted to the door until after 1978. (00:08:58)
Episode #2.6 - S2-E6
Factual error: In the back of the record shop amongst the audio equipment you can see 2 A&R Cambridge A60 amplifiers. These were not available until 1977.
Suggested correction: The show is set in a form of purgatory in 2006. It's not really set in 1973.