I'm pro side passenger awning even though the points about it being quite high are well founded. We added ours when we purchased our used TC. It did not have a rear awning and they told us they couldn't mount one there because of how it was constructed.
Anyway, we ASS-u-med the side awning would run the entire side of the TC .... like our Class C awning did. When we picked the unit up ... it the awning fell well short of covering the length of the TC. They said they didn't want to have an "exposed" inside mounting bracket so they "hid" the bracket in one of the upper sleeping area cabinets.
It could have easily have been 2 feet longer and we wish it was. Any exposed bracket (which is quite flush with the wall) inside could have been tastefully covered up in any number of ways. My advice is to ask how long the awning will be and as one of the earlier posters suggested, have them physically show you the mounting points they would use.