As far as the TRBO goes, Nascar is very clear that they are the only ones allowed to be using TRBO or encryption. It is also my understanding that the big teams were banned from using TRBO even for non-essential communications towards the end of 2013. I used to intern with a small Nationwide team (no one on the team could have told you what TRBO was). The how stuff works article seems to have good info, but leaves some info out. Racing radios supplies probably 75% of the Nationwide series teams, while probably only 50% of the sprint cup teams use them. All teams (Despite their radio provider) are required to bring an actual car radio (mostly the Radius CP200) to the NASCAR hauler which houses a mobile Racing Radios shop. They will ask you which channel you are going to use and pull up the programming off that radio to confirm their list (sometimes they just plug in a handheld mic and turn on their scanner further into the season to see if it is primary or backup and highlight the one you are using on their sheet). They then program their receiver bank of about 50 rack mounted base stations so that every car has a radio. The feed from this rack is fed to the TV broadcast, Race control (to monitor for rule infractions), and to Raceview and the FanView things that they rent at the track. Each series has a Racing Radios shop in it's hauler, Sprint Cup has a radio hauler, Nationwide series has a hauler lounge, and I have never seen the one for the truck series. If you have any questions, feel free to ask me here or PM me.