Risky Business (1983) on Netflix

Left alone in the wealthy northern Chicago suburbs with the family house and Porsche at his disposal, Joel, through his scheming friends, finds himself entertaining to-die-for lady-of-the-night Lana. After meeting Joel's enthusiastic friends, Lana spots a business opportunity, and suggests bringing in some of her equally stunning colleagues. Joel is aghast at such an idea, at least until the Porsche accidentally falls into Lake Michigan, requiring a quick infusion of ready cash.