It's the question we get more than any other: should I buy polyurethane or fiberglass? Both make excellent Porsche aero parts, but they behave very differently on the road and in the body shop. Here's an honest breakdown to help you choose.
Polyurethane: flexible and forgiving
Polyurethane - including our proprietary GT3TEK blend - is a flexible, impact-resistant material. When it meets a curb, steep driveway, or road debris, it flexes and returns to its original shape instead of cracking. That resilience makes it the smart choice for daily-driven cars and for parts mounted low on the vehicle, like front lips and side skirts. It arrives ready for scuff, prime, and paint, and it holds OEM-style fitment well.
Best for:
Daily drivers, street cars, front lips, side skirts, diffusers, and anyone who wants durability and easy ownership.
Fiberglass: sharp, detailed and rigid
Hand-laid fiberglass holds finer edges and crisper detail than polyurethane, giving an authentic, period-correct look that's prized for show cars and large conversion panels like full bumpers. The trade-off is that fiberglass is rigid - it doesn't flex, so impacts can chip or crack it, and it should always be handled and installed carefully. Fiberglass parts arrive in a raw gel-coat finish and almost always require body-shop prep and fitment work (sanding, reshaping, gap adjustment).
Best for:
Show builds, classic restorations, full bumper conversions, and buyers willing to invest in professional installation for a flawless finish.
Side-by-side summary
Durability: polyurethane wins for impact resistance. Detail & sharpness: fiberglass wins for crisp lines. Installation: polyurethane is more DIY-friendly; fiberglass benefits from a body shop. Maintenance: polyurethane shrugs off curbs; fiberglass needs care. Best use: polyurethane for daily aero, fiberglass for show and conversions.
A quick note on installation
Whichever you choose, professional installation gives the cleanest alignment and paint match. Fiberglass in particular is not a no-prep, bolt-and-go part - if you're not willing to sand, reshape, and adjust gaps, choose polyurethane or budget for a body shop.
Shop by material
Most of our catalog is polyurethane for that daily-driver durability, with select fiberglass options for show and conversion builds. Browse your chassis collection - 997, 996, 991, 993 - and check the material on each product page. Still not sure? Our full Porsche aero buyer's guide walks through every part type.