When we installed a LQ, we framed out the ceiling and walls with wooden studs. Except for the ceiling's center which has a slight upward bowing, the corner transitions were then pretty much squared up. We installed precut paneling, formed using cardboard templates, covered with an automotive headliner material; a blast from the 60's, a favourite of the owner.

The studding made the insulation, wiring runs, plumbing, electrical box placements, lighting boxes all much easier to install. It also made the installation of the paneling and cabinets much more secure.

yep I figured it out allright! Sell it and buy one that's already done!
Excellent!!  I wish that were an option for me  :-)

Gard - tomorrow we are installing the ceiling into my trailer.  We have the entire LQ space studded out.  The ceiling has wood strips that have been cut to allow it to follow the curve of the ceiling.  The material is the bathroom panels from Lowes that have a textured surface.  The strips on the ceiling (side to side) are about 18" apart with a strip down the center as well.  My question is about sagging.  Do you have any experience/knowledge about how this material stands up to hot temperatures?  The LQ area is fully insulated, but it still gets warm by the ceiling.  I know that if it sags, DH will tear it down and try something else - he is quite the perfectionist  YOu are right about the studs - they make putting in the electrical quite easy and neat.

This creates an excellent storage space, and does square up the forward cove, making the ceiling to wall areas easier to fit.

Remember when making the face frame, to construct the bottom rail almost a foot in height. This will allow the doors to open above your mattress, bedding and pillows, without having to move them each time access is necessary.