Hard At It (1971)

A couple, Bill ("greaser" porn actor Henry Ferris: ugh-h-h-h!) and Cathy has their car break down -it looks like a vintage Daimler. They go to a nearby house to use the phone (probably the corniest plot device, so often repeated in porn history) to call a garage. Lady of the house Cindy (sexy Carmen Olivera) introduces them to swinging.