Ok, thanks for the thoughts, we tested two today to see what they're like as I've never driven a TD4 before. First we drove a Maasi Mara that had just come in, and to be honest a bit out of our price range at £6995 (think its a 53 plate) thought it was very smart and tidy, the clutch felt so light and springy and all gears engaged cleanly. It drove well and handled all the different terrain we could find (had it out for about 45mins on main roads, back roads, bumps and pot holes, had to pull off for a couple of tractors and very impressed with how it felt on the snowy / muddy grassy verges) but I was concerned by a slight whirring or whining which seemed to get louder as we accelerated and quieter as we slowed down. You could only really hear it if you listened hard for any noises.
Then we drove the cheaper one of the two I listed in my first post, a Kalahari. The salesman said it had only been in two days, but when I let the handbrake off, it felt like it had been sitting for weeks - clunk! If he was telling the truth, then maybe it has some break 'issues' ? But the breaks actually felt sharper than the Maasai Mara. It has a few obvious faults, such as the passenger window going down but not up, a hefty lot of blue and very smelly (dieselly pong) smoke when it was cold and a very gentle 'clunk' coming through the steering wheel which I only noticed as I was parking it back in the yard. I had a similar symptom with my car when I first got it, and it turned out to be suspension strut bearings. I got my mum to turn the steering wheel one way and then t'other, slowly, and I could see the front spring sort of juddering, or snagging. Again, the clutch felt good, light and springy, and all gears engaged cleanly, but I again I could detect a very slight whirring noise, but not quite the same as the first car. Is this a general transmission whine or a sign of something terminal? There's no MoT on it, so I would like to think the garage will give it a good check over.
Anyway, was quite fun driving the TD4 for the first time and getting an idea of what things to look for, although I don't think the dealer will want to see us for a while as the Maasai Mara managed to lock all the doors with the keys in the ignition and the window on the Kalahari wouldn't shut!
PS, was also surprised at how easy they are to reverse park.
PPS, was disappointed that there was only a radion / tape player in the Kalahari :-(