Yea. Your on about the Black Stig, Perry McCarthy. He drowned in the north sea lol!
They killed him off after he revealed himself.
But regarding the 'James May is the Stig' thing, they can do double takes and edit it to make it look like James and Co. are watching the Stig (James(!)), driving around the track.
Well whoever the Stig is he's intellectual property pwn'd by the BBC....
"The Stig's identity remains under wraps as press barred from court case".