What size is the Torx bolt that holds the rotor on on an 05 cooper S ?

 

Torx head size T50 .

The bolts should be replaced every time you do a brake job / rotor change and you can apply the anti seize to the head of the brake rotor screw.

One rotor screw per rotor.

http://www.ecstuning.com/Search/07136772426/ES16458/



Thanks and let me know if you need anything else.