How can anybody attempt to justify owning a new car by "saving money"?

First, you've got to factor in the ?30k (a *shitload* of money for
something that size) that's tied in to the car, and the loss of return on
that. Let's say 5%. There's another ?5 grand to factor in  over three
years.

Now bear in mind that the residuals on BMWs/Mercs and the like are
calculated against the list price of the standard spec without options. You
can't sell a used BMW or Merc that's not had the option list thumped hard
against it. They just don't sell. And the options aren't cheap.

Finally, factor in the likelihood of a backlash (or even just a slump in
used values because of oversupply and the fashionability fading) against
"lifestyle SUVs" like the X3 in the next couple of years.

Unless you're leasing, in which case you *know* what it's going to cost but
have a completely different can of worms with condition and mileage
potentially biting you, don't bank on the residuals.

If you want to drive something newish *and* save money, buy something 6-12
months old that's lost a big chunk of the original list price - and that
means something less "fashionable" and "bling". If you want an X3, fine -
your choice - but don't try and justify it as "saving money".

Still, at least the X3 isn't American like the X5 and ML, it's Austrian-
built, in the same Steyr-Puch factory as the Jeeps. Steyr-developed, too.

Yes, but you seem to be ignoring the fact that the X3 is crap. It's
positioned with regard to 4x4s as the Alfa Sportwagon is to estates.

As others have said buying a new car isn't going to save you money, no
matter what brand you buy it's goign to cost you a thick wedge to buy a
brand new car. Most of the depreciation is in the first year, that will
see you lost about a third of the value of the car in year 1. If people
wake up to how shite the X3 is, that could increase to as much as 50%.

You haven't actually said too clearly why you want a 4x4. There are good
reasons for preferrign one over other vehicles - living in the country,
hauling largish loads, living north of the border (Scottish, not M25) or
above 1,000 feet would all push someone in the direction of choosing a
4x4 over other vehicles. In most of these stakes the X3 and particularly
the underpowered 2.0 diesel (do you really want to pay 91p/litre for
your fuel?) is going to be a pointy, jagged, razor edge shape in a
sensitive, hole lined with pain receptors.

The Nissan is an excellent vehicle, nice compromise between on and off
road and with a very practical interior. Big, boxy, fold all the seats
down and the surface is wipe-clean. If you want 4x4 for some illusion of
security (and the advantages are mostly illusory unless one really want
to get into slippy stuff) then a Subaru Forester is a damn good choice,
as is a Legacy.

If it's simply driving position, buy a minibus or something.

Personally, if a normal saloon is a possibility and you don't really
need the 4x4 option you would do better with something like a BMW
5-series or a Volvo. But never new, and avoid "demonstrators" as well.