I am considering changing my 2001/51 BMW 525dSE Auto with 74k miles and a full BMWSH. It has run like a clock for the six and a half years I have owned it and had one previous owner. It is valued at around £4,500 for trade-in. The replacement will be either another 5 Series (but the 520d SE variant with auto). Or I have been offered a January 2008 Audi A6 2.0 TDI SE with auto (CVT) and a lot of ‘bells and whistles’ (leather, sat-nav, metallic paint) and only 3,500 miles on the clock for £21,500. It was pre-reg by local Audi franchise and has sat around at their PDI centre doing very little for 15 months. This seems to be a good purchase but is it fairly priced and why can’t they sell it? My quandary is does it represent good value against a BMW 520dse with ca 20K miles which should come at around £20,000 (my budget) so is it worth the premium to have a lower mileage car? I am aware that there will be a new A6 coming shortly.