exhaust for convertible

I have an 05 convertible non s, looking for an exhaust but cant find one for a mini cooper convertible, they all say not for convertible, please help. Anyone know a brand that sells for my car, if you do please post were to find.

I think that they all fit, not sure why they would say not for convertable.  I know for a fact that the Milltek works, it's the nicest in my opinion anyways.