Valentino Rossi is no stranger to Formula 1, with his most recent adventure in the sport seeing him drive the Mercedes of Lewis Hamilton.
It isn't the first time a star name has made an appearance in F1. While they are usually a PR stunt, sometimes the appearance leads to rumours and serious discussions.
Here are five special guest appearances in Formula 1 that you can see in the photo album below.
Formula 1 is reserved for some of the best racing drivers in the world. What if you got a chance to step in a car? Here are five people that didn't hesitate to take up that offer.View the album