My car is due for a Cambelt change and MOT. I got a quote of £399 + £54 from my local Audi Dealer and a quote of £288 + £39 from a good local garage. Is it worth spending the extra £126 for Audi servicing? The car has mixed service history most of which has been done by an Audi specialist by the previous owner. I recently had the brakes done by Audi under their fixed pricing scheme. Any thoughts?