I have to agree that it cannot be Danica because road circuits are not her thing but who is the other Indy driver Mark W (something) that rules at road courses?
If it is Tanner I don't think that would be a good choice on the producers part. Simply because he could show a bias to a car. The UK Stig just likes to drive the car into the ground.
Hey I guess we could possbily find out if this show ever turns out at a Chumps Car or Lemons race. If we don't see the Stig plus Tanner in the pits ...
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if you can only race me in a straight line then whats the point 
...91 SMF SCCA
http://www.flickr.com/photos/8341770@N07/5601083432/http://www.flickr.com/photos/8341770@N07/5601083432/ by http://www.flickr.com/people/8341770@N07/, on Flickr
I see people out there spending money on the car to improve it … If you spend half that effort just working on your driving skills, making you and the car work together as a team, then you’ll go faster – period. To make the car go a second faster on the track takes a lot more energy and money than making yourself drive it one second faster.
– the late Tom Thrash SCCA Solo E Production