Wikipedia
Lunch Wagon (also known as Lunch Wagon Girls) is a 1981 sex comedy starring Pamela Jean Bryant, Rosanne Katon, and Candy Moore.
The film was directed by Ernest Pintoff and written by Marshall Harvey and Terrie Frankel and Leon Phillips. Mayor Bradley declared "Lunch Wagon Day" for the opening, and there was a parade of over 80 Lunch Wagons down Hollywood Boulevard. The film was very popular with teens and was the largest grossing independent movie of 1981.
Usage examples of "lunch wagon".
What I mean is, at a lunch wagon on a country road there's no way any man I send could make himself invisible.
Picked up the frequency they were using to coordinate the phony work crew with a phony lunch wagon on the other side of the park.
Heller had everything gathered up and they went off and bought sandwiches and pop from a mobile lunch wagon.
But, strangely enough, neither the fishermen nor the peanut man paid any attention to those who hung out in the lunch wagon.
It seems that life in the jungle is rather more like life at a short-order lunch wagon than I had supposed.
Glancing at the sun, he saw that it was still an hour or more till noon when the lunch wagon would come driving down the rows.