Sacrilegious, for sure. I would be afraid to do something like that.
I know a pastor who got upset with a deacon because the deacon had told someone (regarding a matter during a service) to "just slip out during one of the prayers so no one notices you". The pastor told me he was upset that the deacon did this because he said that, during a prayer, the one doing the praying is talking to God.....the Creator of the Universe. It should be a holy moment. Why in the world would we think that would be the right time to "slip out" of church?
I agreed with that pastor. Prayers should be serious and not just something done as a formality at a ballgame, car race, or even because it appears next in the church bulletin. When it becomes routine (or as in this NASCAR event, entertainment) it is no longer a prayer.