I have been spoiled by having a '99 Mondeo estate 2.0 petrol which has been AMAZINGLY reliable despite neglect and abuse, is currently still going strong at 152k miles and returns 40-42mpg on a run. I have a lot of trust in this car, but the bodywork is going and I am faced with an imminent situation:
I will have to do 450+ miles every week, and
I HAVE (advisedly) to spend £4k-£6k on a car (I must tie-up this amount of money as a justifiable expense).

The travelling situation is likely to continue for between 1 and 5 years. But the tying-up the money situation hopefully only about a year or two.
After the travelling situation ends, my mileage will revert to something low like 7k per annum, and I will be happy to run a banger (for local duties) alongside a cheapish classic (for automotive interest).
After the tying-up situation ends, I could revert to running a series of £650 1999 Mondeos...!
So on the one hand it would be nice to have had a low-depreciating car and get a good chunk of my money back.
Buying an OLD car which is currently worth £4k is the obvious way to try to avoid depreciation, but this purchase has to appear justifiable on sensible/reliability logic grounds, not on "fancied something flash/classic" grounds. So it's probably going to have to be something on a registration letter between about 05 and 58.
I suppose I could just about stretch justifiability to something like a pre-1996 Mercedes diesel estate, but the ones in my price-range already seem to have over 200k miles on them, and they're not THAT economical. (Hmm- -perhaps could run on old veg oil from the local takeaways?)
And fuel economy can play a big part in the overall equation:
26k miles pa at 40mpg is approx £3900pa; at 60mpg is approx £2600pa, so if I can get a car that will do nigh-on 60mpg, I'll be saving myself £1300 a year anyway, and the longer the tying-up situation persisted, the more (fuel) money I'd save...

The thing is, looking through HJ's Car-By-Car Reviews, it genuinely seems almost impossible to find any diesel car that doesn't have the potential (maybe even likelihood) to go wrong in one or more expensive ways!
PSA 1.6 HDI used in Ford, Mini?, Citroen, Peugeot: Fuel pump issues . DPF/fluid issues
Fiat 1.3 and 1.9 also used in Vauxhalls- waterpump seizes, shreds timing belt, bends valves
VAG used in Audi, VW, Skoda, Seat and others: piezo injectors, ECU software even in old 110hp 1.9; coolant loss due to porous cylinder heads, oil pump drive fail, Teves ABS issue.
Nissan 136hp: Turbo will likely fail
Renault: EGR valve, potential to run on sump oil
Mazda 2.0: Large potential to run on sump oil. Likely DMF issues.
Toyota 2.2: Large potential to blow head gasket
Toyota 2.0: "Don't reckon on very high, trouble-free mileages for these engines"
Honda 2.2: Failed turbos, high oil consumption, poor economy, Teves ABS issue.

It almost seems like only the old 1990's PSA and VAG 1.9 normally-aspirated engines have assured longevity. It's almost enough to drive me to consider trying to find a mint Peugeot 405 non-turbo.

So, my QUESTION 1:
Does ANYBODY make a turbodiesel engine that isn't a complete and utter gamble?

The only ones I haven't heard TOO many bad things about seem to be the Toyota 1.4 and the Kia 1.5 (though is the latter just because there aren't many Kias compared with VWs?)

Even petrol engines seem to be a gamble:
Vauxall 1.2 and 1.4 snaps camshafts
Toyota VVTi drinks oil.
DMFs again

I'm seriously considering an LPG petrol car, but
Fords and Toyotas suffer burnt valves and valve recession
which (factory-fit-wise) leaves Vauxhall, Saab (Vauxhall engines with higher parts costs), Volvo (higher servicing costs)
and Vauxhalls overall seem to be less reliable than Fords, and with poor depreciation.

The other dilemma is body style:
A saloon is pretty-much ruled out, but I like having a big boot that I can just chuck stuff in without having to do a jigsaw puzzle, and I will be carting quite a bit of stuff about on these weekly trips.
But most of the time I only need 1 or 2 seats, so I COULD possibly get away with a medium (or even smallish) hatchback with the back seats down, but I'd have to arrange for some kind of second roller luggage cover to hide the entire payload from view.
But would a small hatchback allow me to transport a washing machine or fridge-freezer? That's been a convenience with the Mondeo, rather than have to wait-in for deliveries.
Also, when doing this amount of mileage on fast multi-carriageways, I'd feel happier having a longer crumple zone to the rear of the seats.
And traditionally it seems the economy of diesel engines isn't badly impacted by a larger body (e.g. Audi A6 1.9 could still do 50+ mpg), so it seems I might as well get a bigger car rather than a smaller one, if it falls within the window of choice.

Another consideration: In general, I prefer the driving position of a 'normal' car rather than an MPV. Though I will consider an MPV if it has a 'normal' driving position.

On the face of it, a Skoda Fabia Estate might nicely fit my needs, but the diesel engines will share the Golf's issues (as might an Ibiza estate), and those supposedly-economical small petrol engines A) May not be so economical in the real world, B) probably have direct-injection of dubious reliability, and C) may not offer sufficient overtaking oomph

Oh yes, another consideration: About half of my journey is on single-carriageway A-road. The 2.0 Mondeo can overtake one or two HGVs in relative ease and safety. I'd prefer a reasonable amount of overtaking capability.

An Astra estate would fit the bill, but there are issues with the diesel and petrol engines/drivetrains.
A Focus estate would fit the bill, but there are issues with the diesel and petrol engines/drivetrains, and road noise from the back wheels.
A Hyundai i30 or Kia Ceed estate would fit the bill, but the petrols have short gearing, giving unrefined cruising.

The only other small estates are the 207 and Clio, but as a big generalisation, french cars are not renowned for reliability, and the diesel-engined versions are just beyond my price range. Clio cheaper with 1.2 turbo petrol, but is that real-world economical?
The Meriva has the Vauxhall engine issues and "doesn't feel very stable at speed".
The Fusion isn't really bigger than a fiesta to a worthwhile extent.
The Zafira has a deplorable reliability record overall (and is a 'Which?' "Don't Buy").
The C-Max's boot, seats up, isn't very big: It offers nothing over a Focus estate.

Ooh, one other consideration though: Due to popularity with the rest of the public (not me), is it possible that a mid-size MPV will hold its value better than the equivalent estate?
e.g. Zafira rather than Astra Estate, C-Max rather than Focus Estate...
For example, all things considered, one vehicle that may tick most of the boxes is a Toyota Corolla D4D estate. But surprisingly, I find that examples of Corolla Verso are currently similar prices but often with lower mileages. The estate is very bland. The Verso is no oil painting, but is it possible that in a further few years the estate would never attract a buyer, whereas young families are always looking for an MPV??

The Renault diesels don't look to have too many issues apart from keeping an eye on the EGR valve, but I've driven a Modus and I didn't much like:
the driving position, the over-servoed brakes, the cable gearshift, and the feel-less electric steering.
Is the Nissan Note any better in any of these respects?

So, my own shortlist seems to be becoming:
Hyundai i30 1.6 diesel - preferably estate
Kia Ceed 1.6 diesel - preferably estate (Kia also has the advantage that any diesel drivetrain shenanigans might be still be covered by its 7-year warranty, although the ONE diesel estate I found in the country for less than £6k and with less than 80k miles was a 58-plate that already had 74k miles on it!)
Toyota Corolla 2.0 diesel estate
Toyota Corolla Verso 2.0 diesel

In order to consider the Toyota 1.4 diesel engine, which is more economical than the 2.0 and appears to have fewer issues, I'd have to just get the normal hatchback.
If I do that, I find that they seem to be priced higher than the 2.0!
And if I'm going to consider 'normal' hatchbacks, I was astonished to find a Kia Cerato 1.5 diesel with just 27k miles on it, for less than £3k! Yes its looks are rather sad-sack, but it's a chain-cam with very competitive power, emissions and economy, and if it's reliable there is a lot of life left in it, and the bad depreciation would be offset by the much-lower purchase price...
After all, if my situation continued for 4 years, I'd have added a further 100k miles onto whatever I started with.

A QUESTION:
Does the Toyota 2.0 D4D have a DPF?
Do the Hyundai and Kia 1.6 CRDi have a DPF?

And then I found the the thread about Ethan Edwards's Nissan Note 1.6 petrol that he'd had converted to LPG by a reputedly-reputable firm.
Seems as though if you can get a decent installation, there aren't too many drawbacks, and if the LPG system goes wrong, unlike a complex diesel going bang, you can usually just revert to petrol operation until it gets fixed.
Are there still benefits for London users of LPG cars (not that I drive in London - I'm thinking of resale opportunities)?

So, can anyone convince me of one particular solution?!
Have HJ's "What's Bad" column inches made me bogged-down in huge paranoia that isn't generally representative of the real world?
I'm drowning!