I have painted more than a few cars over the years - lacquers, urethanes, alkyd enamels, and base/clear. The deal with some of the "fast" paint shops is that they should be relatively good at the application of the paint, and poor at the prep, where all the labour is. They should have a lot of practice at painting because they do so many cars.
When you say that there is a dry or extra orange peel stripe down the middle of the roof, it means that the painter is inexperienced or short, or both. The dry stripe is a give-away, as is the dry spray on the bottom edges.
Also these shops tend to limit the amount of material used on the job, so they apply it sparingly, which if it is properly reduced can produce a level surface, but a thin one. Inexperienced painters produce orange peel when faced with a limited amount of material.
It is a bit of an art for sure. No good painter would ever suggest that his work should be "colour sanded". And of course, on a base clear, it isn't a "colour" sanding at all, rather the clear is wet sanded and polished back to a gloss. That process in itself is far more costly than using the correct amount of material, and spraying it correctly the first time.
There isn't a whole lot you can do.