Don't see the pic but I'm pretty sure I know what you're talking about and yes it is replaceable. The driver's side leaked on my car and a 2010 that I installed an exhaust on. The dealer replaced mine no problem. I think that this is a more prevalent problem than people realize.
2008 IB E92 M3| BBS | KW | Arkym | Platte Forme A.G. | Active Autowerke | K&N | Fabspeed | Dinan | Evolve-R