The fiberglass on my 2-year old Sonic (Venture aka KZ) started delaminating near the curve of the back roofline. Discussion with the dealer revealed it was a know issue caused by a design and manufac...
RV Industry generally puts out cheaply constructed products excluding some like AIRSTEAM. That's one of the reasons I don't like laminated plastic/fiberglass on an RV unless screwed or mechanically fastened . The constant heat /cold/ humidity and vibration eventually loosens the glue and you will get separation. A Matter of time I prefer the alum. siding for that reason. Aluminum is not without its problems but easily repaired and doesn't delaminate.