Go for It (1983)

Doug is driving a truck when he picks up a hitchhiker, Rosco. Traffic police stop them for a control but confuse them for two robbers. They manage to escape from this situation in a very strange way, only to fall into a worse one. They run to the airport trying to take the first available flight. They not only score a free flight to Miami, but also someone gives them a bag containing $1-million.

Later, Rosco and Doug will understand that this time they were confused for two secret agents but now they are too deeply involved in the situation.