So I jump in the other morning and the Low Coolant Warning sounds. Shocked, because I'm on my second rad in a year and have been checking the header tank every 3 to 4 weeks with out losing a drop. Sure enough, it took about a pint and a half to bring it back to level. Noticed some stains on the drive around the front of the car though and some dampness on the under tray.
Out comes the torch and I search all the usual suspect places and even the LPG connections but no sign of any drips or staining.

Did a 200 mile trip and left it to cool down before checking. No sign of a drip and water level fine. Drove back and 200 miles later, same result

On to the ramp today and stripped off the under tray. Pressure tester brought out to play and having pumped it up, stood underneath with my torch and awaited the drip (s). Nothing although the pressure did drop a touch.
Not going via the head gasket as we did a sniff test and there was evidence the other day of drips.

So where did it go ?? Bigger mystery than that missing plane.

Have you seen this thread

http://www.fullfatrr.com/forum/topic23001.html

The antifreeze has got to go somewhere  If it dont work.......burn it!

If the IId tool cant fix it.......burn the FF.

If the FF cant be fixed......buy a Land Cruiser!

If the LC cant be fixed..............................................BUY a horse !!

Yep. Changing the transmission oil cooler, the thermostat that operates with it as well as the backing plate that attaches it to the rad some time later this week as the black plastic parts have been known to become brittle and weep.