A long glass reinforced thermoplastic horizontal “Class A” panel technology is discussed, based on compression molding of polyethylene terephthalate (PET) based stampable sheet. Molded panels can withstand temperatures up to 200°C for 30 minutes making them paintable on-line along with steel panels. Class A surface characteristics have been demonstrated in actual assembly plant paint trials. The panels also show mechanical properties competitive with thermoset sheet molding compounds (SMC), but at significantly reduced weight. Recyclability via remelt processing or depolymerization is discussed as a key advantage for PET-based exterior panel systems.