Q7 4,2tdi

[Joe2.0E]

Sounds like one to definitely walk away from. Low mileage used cars can often mean a chunk of time "off the road" for all sorts of reasons while being sold as repairable salvage, insurance settlements and then a bodge/repair with cheap secondhand parts.
The annoying part is the clear hpi check data in the ad.

[Ameiseuk]

Didn't even get as far as a test drive, just too many things didn't stack up.
The spec and dvla supplied chassis no has aroused my suspicions