screeching from rear wheel

the vrs had its 1st service (at 9999 miles on the clock hehe) with no probs

however afterwards there was an awful intermittant screeching/rubbing from the rear of the car

i thought it was something the garage had done, but thought i would check first before the hassle of returningto the service dept

narrowed it down to one wheel, took it off and a large bit of gravel was wedged between the brakedisc and the metal cover medial to it - when i was driving it was rotating and causing the noise.

simple enough fix, but the first time it has happenedn probable ~ 250k worth of driving....