There are only Three cameo appearances which have not been clarified.. these are as follows :

Episode 3 of Series 9 was set in the United States, with the presenters purchasing American cars and driving them across four states while on holiday. One of the challenges set for the presenters was for the cars to set a lap time around a racetrack, for which "the Stig's American cousin" was introduced. Nicknamed "Big Stig" by the presenters, this Stig was overweight. However, he was skilled enough to record lap times for two of the cars, although he had trouble with Richard Hammond's pick-up truck due to weak brakes.

Episode 4 of Series 10 featured the presenters driving across Botswana. To test the performance of the three cars used by the presenters around a dirt rally track, Clarkson introduced "The Stig's African cousin." This incarnation of The Stig had black skin, wore only Puma shoes, a loincloth and the iconic white helmet. He set lap times for two of the cars, but walked away from the track when Clarkson's Lancia Beta failed to start. The others joked that African Stig was trying to get a respectable time, so didn't bother using the car as it was too slow.

Episode 10 of Series 10 featured the Stig on vacation in Spain. In scenes where the Stig was lounging around a swimming pool, a bikini-clad woman appeared in the background wearing a version of the Stig's racing helmet. This woman's connection to the Stig has yet to be revealed.