I am going to be going to watch a Nascar Nationwide Race in June and was just wondering if the frequencies they use in the 450 - 470 MHZ range are in the FM or AM Mode.
The best site to get updated frequencies for all Nascar (Nationwide & Sprint) is Race Scanners Racing Scanners Race Scanner Racing Headsets Racing Frequencies NASCAR Frequencies Racing Radios Radio Headset Electronics.
It costs $20 per year, but they update sometimes 3 times a week (for entry list & freqs, for qualifying, and the race itself). There sometimes are some freq changes for a few cars, and definately at the beginning of the year when some drivers and driving different cars and for different sponsers, this is especially true. Great site - I use it all the time for reference in case I go to a race. And yes, the freqs are in the 450-470 range.