Abstract: Compositions, apparatus and methods of the present invention concern the manufacturing parts that remain strong and dimensionally stable after exposure to e-coat painting conditions. Such manufacturing includes providing a molding compound having about 55-65% by weight polyethylene terephthalate content, about 35-45% by weight filler content, and optionally about 1% by weight blowing agent content. When an injection molding machine is provided, the molding compound can be fed into the injection molding machine to form a raw part. The raw part can then be removed from the injection mold and quenched in a quenching bath to produce a hardened part. The hardened part can then be secured to a partially assembled vehicle. The hardened part, along with the rest of the partially assembled vehicle can then be electro-coated, painted, and baked to produce a final vehicle or sub-assembly thereof.