My wife and I went to the fall Charlotte race in '97 and spent
about five days total in the area for qualifying and such. Somehow we got ahold of a map of where all the shops are located and visited several. At Robert Yates shop you could go
into the lobby and look through the window to the back where
the cars were (at the time this shop was pretty much in Charlotte). North of Charlotte was an industrial complex (might be the same Wayne mentioned) where we found Felix Sebates,
Kranefus/Haas #37 (Jeremy Mayfield) shop, and Penske had a
shop there. These shops didn't give tours but you could look through the glass to the cars. Then we found the MB2 shop which was off the beaten path in a little industrial park. It wasnt a high
dollar operation like some of the bigger ones, as at the time Derrick Cope was driving the car but it had been announced that
Ernie Irvan was taking over the following year. The receptionist took us on a tour through the back where they build the cars and spent about 45min showing us around, and even gave us a handfull of skittles bags before we left. If you can find a smaller operation you might have better luck getting a tour. I think my wife found the shop maps on the internet.
Galen