Gary,
The last times I was in a Prevost shop they did not prohibit anyone from watching the mechanic. I have been in the NJ, FL, and the TN shops and all allowed the customer to watch the work.
The only time they prevented owners from being in the shop was in 1994 or 1995 when Prevost moved from the old shop on Wilson in Jacksonville to the present one. As soon as I was prevented from being with my coach to observe the mechanic I decided to never again allow that to happen and from that point on I have done my own work.
They have since changed that policy. BTW It drives me nuts when people claim they cannot allow anyone in the shop for "insurance" reasons. What a bunch of bullshit and lies that is.