My Mk1 cortina was lighter than the Mondeo. But what's the point of those sort of comparisons?

The Mazda is expected to be lighter than its equivalent rivals, thats what relevant.

1570kg is quoted for one of the heaviest versions, so entry models will be lighter.

This compares well to the same sized car the T30 xtrail. which weighed 1650kg in SVE.

As you know most of the fords have gained size, which accounts for the increased weights.

To gain a sense of perspective. I'll throw just one more in: 2001 Ford Mondeo 2.0i-which everyone will agree is a fairly cavernous car that'll easy accommodate 5 passengers and the kitchen sink. Weight: 2860lb (1300kg).

5 passengers? Where does the driver sit? :P I had one of those Mondeo's and the rear space isnt that brilliant, the car will seat 4 with no problem though. It was a good car but i think its 2-star safety rating had something to do with the successor becoming bigger and more chunky. 2 star wasnt too bad when the car was developed in the 90s but it'd be deemed unacceptable now.

It isn't really clear what all that weight is achieving-it certainly isn't cabin space. I suppose a half baked 4X4 system engenders a comforting illusion of invincibility.

Safety features? Stronger construction? Strengthening beams? etc. All of that stuff must weigh quite a bit. My S-Type's door is far thicker and chunkier than the Mondeo that you mention, for instance.

I dont quite see your logic. Yes the aerodynamic safety-centred designs cut down on visibility but most accidents caused by poor visibility endanger the person the motorist hits, not the motorist themselves. In many modern cars its easy to reverse over a child, crash into a cyclist obscured by a door pillar etc but i dont feel they cause an increase of the sort of accidents which kill car occupants.

Its worth noting the Euro NCAP test is a 40mph crash into a concrete barrier and its tested on how safe the vehicle occupants would be. The sort of accident which could kill you is the type you'd probably see coming but its the sort of accident where something hits you, not the other way around.

Just because you can see doesnt mean everybody else will be driving properly and nor does it mean you'll be able to do much about it.