The delivery truck used in the last scene has a black license plate on the front with white numbering that ends in 11, but when the angle changes to view the back license plate, it is white with black numbering that ends in 31.
After Dan leaves the diner in the delivery truck, he radios HQ to tell them he had his "vitamins", which are sleeping pills. The truck is supposedly being driven while he is talking, a telephone pole is reflected in his windshield, which means his truck is stationary.
Dan Mathews sure doesn't seem to be that serious about security of the shipment of narcotics he is driving. While the back door to the truck may be locked, the driver's door is unlocked when he goes into the cafe.
Dan asks the owner of the drug company for a walkie-talkie for the drug truck. A company-issued walkie-talkie would not work on the same frequency band as the highway patrol radios, yet Dan calls his headquarters with it.
After first truck is robbed and the driver wakes to check shipment in back, as he exits the cab,his hat brim reflects the lights for a brief second. When he opens the rear door, crew is reflected in the door. Right before he closes it, reflections of the actors who robbed him are seen, you can see Julie's light colored skirt and dark jacket.
The pharmaceutical company owner asks Dan if he wants to walk outside with him. Dan says it might tip off the hijackers. However, the police car Dan drove is parked in the company parking area which would be an even bigger tip-off.