We had a second awning installed on our 5er a year ago. We scheduled the work with our dealership. We also had some other warranty issues, and wanted a minor repair done.
The biggest challenge for the dealership service department was how to run the wire to power the awning. And then, where to run the switches. We also had LED lights installed.
They did a great job running the electric wires that powered everything, and everything went through the fuse box/converter too. Because we wanted the awning over the back door (which is on the opposite side of the trailer), we wanted the switches near the back door. They ended up putting the switches in a cabinet in the bedroom, but near the door and a window on that side too.
The total price for the lights, the awning, the labor, and replacing the little amber porch light with a different LED light, because the awning interfered with the original light ran us about $2000.00
Was it worth it? Absolutely YES! We use the back door on the opposite side as our main entry door a LOT more than the front door in the normal location.
When camping, the normal front door is the "front". When home (and we use our 5er 24x7x365), the back door on the opposite side is the "front". The back door gets used a LOT more than the traditional front door. A lot!
So, the price of the awning and lights was worth every penny for us.
EDIT:
FYI, the added 2nd awning is 16 foot long too.