In Buckeye, near Sun City Festival performing a Dual preventative maintenance service on an Amana split system. Completed service in accordance with maintenance checklist. Customer has concerns with AC vibrating wall, recommend the line set be buried. This will involve recovery of system, piping new line set at exterior, and replacing filter drier. In addition, during service, noticed secondary pan is getting water stains from supply ducting. Recommend replacing plenum boxes to system that are the right size for system and have a higher r value. Customer said she rents, and will let homeowner know about repairs.