Engines manufactured by Continental 1920s and 1930s powered about four million cars, which seems moderately impressive. Read Daniel Strohl's list of Continental-powered marques, however, and you'll be floored!
Of course, that list should lead you right to Strohl's original Hemmings Motor News piece. It's true that we're looking at an engine company here, not a specific engine model, but we're still impressed by the vast number of vehicles that relied on Continental power. Thanks to Judge Jonny for the tip!
[Hemmings Auto Blogs, Hemmings Motor News]