The problem with some car manufacturers, (can you spell BMW?) is that new rotors are just barely thicker than the minimum spec. Not certain what Jaguar is doing in this regard.

 

Jaguar's min. thickness is new -2mm. It seems to be the industry standard now and yes, BMW is a real piece of work, those rotors with the regenerative braking are outrageously overpriced.

 

I like to go window shopping in the classifieds (ebay, craigslists, etc) for odds and ends. It's pretty typical to see something along the lines of "USED (insert part name here) FOR BMW (insert model name here)", followed by an inflated asking price that no one sensible would pay. Same goes for Porsche.