If you find something really nice, but has DPF regen issues, or DPF faults, then Jimmy can usually sort it out for you, he is only based in Biggleswade ( so not too far from you ) , very resonable pricing too

He runs a mobile DPF cleaning business, and is no stranger to Range Rovers
O'Rileys Autos Mobile Mechanic
email : orileysautos@gmail.com Mobile : 07833 413071

https://www.facebook.com/rileysautosmechanic/?locale=en_GB

The DPFs aren't known for failing on these, so it comes down to how they're driven. A 4.4 V8 idling away in start stop traffic very quickly fills! As does ignoring an intake leak.

The turbos aren't known for failing. On the 3.6 they were. 2015 Range Rover Autobiography 4.4 SDV8