It wasn't until 2007 that in-wheel TPS systems started to show up. The tire pressure monitors on our 2005 MINIs are actually a function of the ABS/Stability control system. The ABS sensors monitor wheel spin. If one wheel is turning significantly slower (or was that faster?) than the other three, the system would think you have an air loss in one of the tires. So no need for tire pressure sensors in your wheels. However, when doing a brake job, you need to make sure the ABS sensors are connected and working properly.
I thought our mufflers (either a Cooper S or Cooper) are covered with aluminum so I am curious as to yours rusting. It might just be a lot of dirt. Or punctures from rocks hitting it. However, I wouldn't replace the muffler unless you really did have a puncture (you can hear that).
Here is a link to the exhaust system parts diagram. You might consider getting the
JCW sports exhaust.
RealOEM.com Diagram Selection 
