Well, the deed is done. Before he drilled any holes, he put the antenna on a small piece of wood, hooked everything up, and got antenna up on the roof (radio still in coach, of course) to test different areas for the best SWR reading.
He had read up on how to get into the ceiling. (Keep in mind, we just went from gasser to DP.) We have a (real) wood piece that goes across close to TV that has nubs every so often--where the nubs come out and expose screws. Take all that off (carefully!) and pull down on liner a bit and there it is: the upper 'guts' between ceiling and roof.
At the lower (right) back corner of the cabinet above the passenger seat, he drilled a small hole to feed coax up and across to the upper (left) back corner of the cabinet where he poked a hole with a phillips screwdriver to feed the coax up into the ceiling -- to connect to antenna. The coax comes down from the cabinet along the edge of the curtain (unseen) to where we'll hang the mike/radio. The coax in the cabinet is hidden by the books/cds etc.
When dish was in down position, we tested SWR. About 1.5 for channels 1 and 40..so looks like we're good to go. Guess I'll 'owe' him $200 for the install?!