American coach patio awning install

Curious if anyone has done this. I have a 2009 American Allegiance 40x, I am contemplating an install of a carefree Lateral Arm Box awning rear of my existing curbside awning. As there are no side wall studs in locations that will work, I have fabricated angle brackets that should attach thru side wall horizontal molding (drip rail) and down thru roof. I'm a bit apprehensive as Fleetwood states ther are wire bundles inside the extrusion at radius edge. Thanx for any input.. cmaserv@charter.net