Had a demo D5 for a week in late 2019 - lovely car, but that’s it, a car! Doesn’t have the boot space or durability of my D4.
As others have said, buy new for the warranty as you’ll need it.
I bought my D4 as a LR Approved Used vehicle so dealer had to replace a load of bits on it before it reached the required standard. However, between putting down deposit & paying balance to collect the thing it lunched the engine… I was very happy about this as I got a used car with a brand new engine
I understand now that LR Approved Used warranty no longer covers the V6 diesel engine due to chance of catastrophic failure. There were/are two main causes of said failure - spun bearings blocking the oil journals to the crank shaft & mechanical failure of the crankshaft due to stress fracturing. The former, I believe but don’t quote me, was rectified. The latter, in my opinion, is down to engineers removing as much material as possible from the crank to improve efficiency & then using an engine map that produces a shed load of low end torque which then over stresses the crank.
Aside from such catastrophic engine failures most of the problems with D4s & other expensive LR models is down to people skimping on the maintenance. I’ve had my D4 for nearly 9 years now & nothing unexpected has happened to it. It’s needed parts replaced but they are consumables that suffer wear & tear, so have been budgeted for. It’s my everyday car & certainly does more than 2k miles a year.
The one thing I am truly pleased about is that it’s a TDV6 D4 not an SDV6… the difference? - it was one of the early models made in the first 6 months of D4 production that had the twin turbo V6 but didn’t have a dpf!
As already said, the Ingenium diesel engines are shite - they need to be used for good long runs to get the dog to regen & also need to be driven in ‘manual’ mode so the engine revs & exhaust gets hot enough - the auto box doesn’t really allow this to happen, especially on school runs. They also need oil & filter changes annually or 12k miles, or less if doing short stop/start trips!
A bit out of touch with the current model line up but rather than a diesel if it were me I’d actually be looking at a petrol hybrid version… shock horror, never ever thought I’d write that

Will have to take the V8 out after work for some therapy I think!