I'm thinking about buying the Mina rear muffler delete, I've read mixed things about the rearmost mufflers on an R being fairly straight through compared to the XK8 rear box. The part numbers are definitely different. Will I notice much difference at all? It sounds like going for an over axle delete pipe would give me the sound I'm looking for.

It is definately throatier after removing the rear boxes on an R, but not substantially louder.

Is all about your taste and what sound you are happy with.