I can remember when the P38A Range Rover was being developed, the last one on a separate chassis, the engineers had huge difficulty passing the safety test standards then in place - the chassis hadn't got enough compression and the body had too much. It was eventally resolved but taught them that future models had to be full monocoque.

Sorry GB, but that isn't how it works.

I keep hearing this, but it all depends on the circs of the accident at the time and what you hit.

That carelessly abandoned concrete block that the NCAP tests are based on doesn't feature too often in the real world, as you rightly say the rear ender which our OP is concerned about then in almost all cases the heavy chassised 4x4 will be a safer place to be for the rearmost passengers, if for no other reason than the height advantage.

I can only go back to the 70 series Landcruiser which my lovely wife took though some armco/railings at around 50 mph, took the lot out complete with concrete bases, no crumple zones no airbags, the front bumper and chassis took the whole blow and literally did not budge, in this accident the battering ram effect saved her from any injuries at all, and the car still ran and drove, the height advantage and heavy chassismight have saved possible underbody penetration by the armco steelwork, though had the object been an immovable wall then yes agreed the outcome might have been completely different.

Interestingly Toyota have done lots of work on chassis deformation with newer models and the current 120 series LC chassis is indeed designed now to deform, it is considerably lighter at the extreme front end than the older models, i don't agree that separate chassis are finished as regards safety.

I know where i'd rather be in the event of serious pile up, and i'll put my faith in a strong rigid car for the typical events to be found on the road, but each to their own.

edit, oh Lord i hope someone doesn't post that fifth gear head on test crash of an old thing of a Discovery and a modern car in offset front crash, which often gets brought up in this age old discussion, the OP is looking for rear protection.

Interesting that you 1st put down the fact that euro ncap crash the cars into a concrete block but then use how your lancruiser coped with hitting a concrete block to determine how strong it is?!.

Euro ncap have not tested a landcruiser, not sure why, but out of the current models tested against that concrete block, the lowest scoring toyota for adult occupancy protection (apart from the aygo, which is jointly produced with citroen and peugeot) is the hilux, which, I think I'm right in saying, has a separate chassis. In fact the tiny iq scores much better in an impact with the concrete block.

Another important issue regarding car safety, which, as a general rule, is totally ignored. A cars ability to avoid having an accident in the 1st place. A huge, heavy, lumbering 4x4 is going to have little chance of swerving round an obstacle in the road or an accident which has just taken place, instead plowing into the back of the wreckage, potentially killing anyone still in the car.

Like you say, each to their own, but I wouldn't want that on my conscience......

By the way, we have a honda jazz, a car which is just over a ton in weight, is extremely agile, less than 1.7m wide and scores 93% in the adult occupancy protection. Frankly I'd much rather be in it than an old school 4x4 with the agility and responses of a boat