The novel is about a white slavery ring operating in the 1950's.
The scene I am looking for is a drive-in restaurant with a very shapely (not model thin) teen-aged car hop wearing a short skirt and a pill box hat (like Johnny Phillip Morris), serving a young couple in a 1949 Ford convertible (the couple's faces can be obscured by windshield reflection. The girl has a zaftig figure but appears chaste with a pony tail. The car is shown from the front.
I envision the car being on the left (with about 2/3 of the grill work visible), the girl being in the center. In the right foreground is a masculine hand with a cigar suggesting a menacing observer of the girl. In the back ground is the suggestion of an art nouveau hamburger stand with a sign that reads "Fat Harry's"
I plan sequels featuring the same two detectives, Tony and Mindy, and each cover will feature a '49 Ford. That model is chosen because it is highly recognizable and fixes the era.
The style of art work could be described as "pulpy", I suppose, but
should be reminescent of paperback novel covers of the 1940's and 1950's. rod sterling