brakes or rotors

I've been hearing a metallic rattle/squeal for the past few months and I'm hoping I've finally tracked it down to the rear wheels / brakes. Both mud guard / dust shields are badly corroded and appear to be rubbing against the inner brake discs. I've tried to pry them off but they just crumble...

Well I should have known better! When I bought my 96 P38 I was told that it had been modified with engine, chassis and brake upgreades. Certainly the front discs are bigger than standard. So when the MoT test (an annual check to ensure it is roadworthy/safe in the UK) picked up on worn disc...

Can you share how many miles you are getting on a set of tires and also brakes rotors? Please state what RR you have and tires? I don't have a RR yet but on my Jeep GC - I use Pirelli Scorpion A/T 235/65R-17 and got 50k and 47k miles on last two sets. Front brake 63k miles. Thanks