The 5.0 petrol is a lovely engine, but there's definitely a price premium on those, it's costing me over £100 for a full tank and I'm averaging around 16mpg for local journeys (although you'd get more than that on the parkways around Peterborough). Main thing folks say to look out for is rattles from the front of the engine which can mean the timing chain needs replacing - that's an expensive 10+ hour job. (I'm putting money aside every month to save up for when mine needs doing). Just make sure it has had regular oil services!

I can really see why the V8 oil burner is popular though - plenty quick enough, yet much better mpg. I'm not so familiar with what one needs to look for on these, but the FFRR WIKI has a wealth of information in it, and has really helped me.

I would suggest not being too hung up on getting the rear entertainment system - tech has moved on a lot in 8 years and the screens will look rubbish alongside an iPad, but that's just my opinion, and I don't have bored kids in the back of mine

Recently I looked to upgrade my 3.6 TDV8 to the 4.4 TDV8.

At my price point I could not find a 4.4 with FLSH/mileage and Vogue SE without black leather. So I put it on hold and spent a bit of time and money getting my car as tip top as I could. Ultimately I decided I was far better off with the devil I know, I've fixed so many things, and everything works, it has a massive spec, 2 previous owners, a FLSH and so on.

I also took comfort in the words of Harry Metcalfe, founder of EVO magazine and youtuber "Harry's Garage" - he said that the 3.6 is a better drive than the 4.4, in his opinion.