I bought a poly Vorsteiner replica from Ebay. The problem was that there wasn't a good way to attach it. Especially near the top where it meets the bumper. A CF or FRP lip would be fine because it's rigid but the poly was a no go.
2008 IB E92 M3| BBS | KW | Arkym | Platte Forme A.G. | Active Autowerke | K&N | Fabspeed | Dinan | Evolve-R