Does anyone on here have a 1992 model with heated front and rear seats,the reason I ask is I have just bought a set of seats from a 1993 model which has heated front and rear (same shape leather panels as mine) and in my 92 handbook it shows that they were fitted to my year and I wanted to know if the wiring and plugs might be under my old seats so in effect all I have to do is plug and play?

IIRC, they were never an option on pre August 1993 RHD UK models, and I don't believe they would have been an option in Japan either, as you tend not to see heated seats in JDM cars.

The handbook supplied by Lexus for the LS400 covered both LHD and RHD models.

I hope someone can come along and give you a specific yes/no answer.

So do I,but I didn't buy them because they were heated just that they are the same as mine and the drivers seat is better, just would have been a nice bonus .

The two switches for the heated seats are normally located on the wood just above the ashtray so it would be simple enough to remove the ashtray assy ( look at lexls for radio removal tutorial) and have a look for the switch loom behind,if it's there you might have a chance.
I have a C spec import and although it's only the F spec which has the rear heated/massage seats/rear air con the loom is there but not connected.

I went and had a look behind the ash tray and what did I find.................THE SOCKET IN THE LOOM , the switches light up OK so heres hoping the rears are the same,I'm so pleased cheers Steve.

Brilliant news mate!