I found the track they ran on :)

http://www.willowspringsraceway.com/trackinformation/images/RoadcourseLg.gif

Quite a few straights in there, but I see where the RX-8 made up time. Seems to be more of a raw power course anyhoo... with three big straights that I see from my eyes... definately an edge for the big hp cars.

Actually I'm pretty sure the C&D editors said it was the Streets of Willow Track that they used, which has much tighter turns. Never been there, but I think it's near Edwards AFB (just north of LA).
The Streets of Willow Springs (http://members.aol.com/WSIR%20News/index7a.html)

Both of those tracks are in the same Willow Springs complex, near Edwards AFB. The C&D tests were on "Streets". 1:20s on WSIR (the big track) would be impossible/amazing in a stock car (or even a well-modified road car). :) Both are fun tracks to run on.

-Max