City Heat is undeniably a very stupid, throwaway movie.
Its all instantly forgettable, and ended up being a box office disappointment, but it has some fun moments.
Clint Eastwood and Burt Reynolds co-star as, respectively, a cop and a private eye in 1930s Kansas City. The plot is irrelevant, though. Its all about the chemistry between the two tough guys, who mostly play it for laughs. There is a a particularly funny scene, I recall, where each whips out progressively bigger guns in a shootout. (Clint wins out, with a ludicrously long six-shooter).
The movie was directed by actor Richard Benjamin (Westworld) and written by Blake Edwards (The Pink Panther series), who was originally slated to direct but was fired during pre-production.
This image is from the UK press sheet. It was also used on the poster.