As I see it, there are three main categories of components for a trailer or RV.
1. The frame, wheels, bearings, axles, springs, shocks, hitch, levelers, lights
2. The shell. Roof, walls, windows
, doors, floor
3. The mechanicals: electric, lights
, pumps, fuses, breakers, tanks, pipes, toilets, sinks, showers, refrigerator
, stove, battery
Comparing fiberglass campers to stick-built:
3. Same. Most equipment is third party with sep warranties.
2. This is the main difference and the cause of all the misery for stick-built campers, and the rapid depreciation. Fiberglass shells are more expensive to build, and doesn’t lend itself to mass production assembly lines as readily as stick built.