The surveillance scene depicts a full-size US-made van (Dodge or GM) with square sealed-beam headlights. Square headlights were not found on US-made vehicles in 1973; they were not allowed until 1975.
In the opening scene when Gene, Sam, Chris and Ray are walking toward the body, you can see a Direcway dish mounted on the wall on the building behind them. Satellite Internet technology wasn't invented for another 20 years.
Particular jumbo jet in which Sam, Ray, Chris,and Annie are undercover had not yet been manufactured in 1973.
The surveillance scene depicts a full-size GMC/Chevy van with square sealed-beam headlights. This would make it a late '70s or early '80s model. Square headlights were not found on US-made vehicles in 1973; they were not allowed until 1975.