As the grocery store manager and his female assistant talk over the dire situation involving the manager's family you can see the reflection of a hand and partial boom mic pole in the huge glass window adorning the upstairs office.
The Dodge Charger they are driving is a 1969 model, yet when the Charger and the one police car are sideswiping each other and he ends up running the police car off a bridge into a river, a 1968 model is shown.
After Deke and Larry leave Mary at the store to get something for Deke's hand, the windshield of the blue Chevy has a small crack on the left. The very next shot showing the windshield shows a much larger crack.
When they are waiting out the roadblock, and going into the tavern, you can quite visibly see the boom mic off to the left side of the picture. It's visible for the entire scene, probably a good 15 seconds, and it just keeps following the actors.
The radio used to listen to the cops, is in fact, a Realistic CB radio. This type of radio cannot pick up police calls and also is in Single Sideband Mode, LSB, which would make hearing VHF/UHF police band impossible, even if it could.