the Stig changes, Mc Carthy was sacked cuz he couldnt shut his mouth that he was it.
Hekki Kovalinen has done it a few times, notably in the Reno F1 car.
Normally its Ben Collins, he is an ex stock car ASCAR, pick up truck racer type fella, he has appeared without the mask in top gear, once in the EVO rally car racing the skateboarder down a mucky hill (cuz someone left the stig gear back in the office) and also the week where they played football with the 10 Toyota Aygos.
This has been much debated and argued on several circuit racing forums.