Bit more info, I asked my old mate Honest John (loved his column for agesand find the advice is sound and direct)
His replay was
Found out the reason why, by referring to my own car by car breakdown at
hjuk:
Carbon can build up inside rear active suspension height sensors, preventing current getting through and causing the suspension to malfunction. Sometimes they only last 18 months, and cost £1,400 to replace.
HJ
Now I had run into the water ingress causing rust and associated failure (see other posts and links) but this was a new one on me...any thoughts anyone?
Looks like the height senor which Lexus claim is not a problem actually has TWO underlying faults that cause failure...not a good week for Toyota bosses all round