I had a P38 for a few years and have mainly happy memories and a few bad. Trying to drive on the M6 with empty air suspension, but finally stopping when the kids started crying... the tow back home down the M6. Then there was "off-roading" in a lay-by in a forest near Berkhamstead, bottoming out hard and driving home with empty air suspension. Then there was ripping out the air suspension and going all-coil... best thing ever... After I did that I went off-roading at Broxburn when it just glided through deep mud, up bankings, down bankings, through a bomb crater, and towed a stranded Toyota and a Disco out of two separate mud-holes. It was standard road spec (apart from coils) and it just ****ed over everything. Wonderful.
But my mate just tried to sell his diesel P38 and got a bit of abuse on Autotrader because he was asking £2,500 for it. It was an HSE in good nick, so no idea why. Anyway he ended up going for a split new Audi Q3 (please don't ask) and Audi gave him a stonking £5,000 trade-in on it. Shows what they make on new motors I guess.
Anyway they are fine motors, and the best of luck, particularly with that air suspension... ;-)