In reply to Uncle Tom, I respect the fact that you observe silence during the invocation.
As a RFC Chaplain, I have done invocations at well over 100 race events, and believe me, we get it. Obviuosly a lot of people at any race track are not religous, and so I understand if they talk and carry on during the prayer.
I always feel privlaged if a race track allows us to attend an event, and do an invocation. Mostly though, we are there for one-on-one prayers with whoever wants it. Many Drag Racers, such as Antron Brown, won't go down the track without having been prayed over.
I actually get more bothered when I see people being disrespectful during the National Anthem, because of all the sacrafices people made for everyone at that race.
On a lighter side, back in the 70s, NASCAR Chaplain Brother Bill Frazier told me they started broadcasting his entire sermon on Sunday mornings over the track's loud speakers. He said at tracks like Darlington and Talladega, everytime he paused, a loud chorus of drunks would shout "Amen brother!".
NASCAR decided to go back to just broadcasting the Invocation.