I think I've been very lucky.
I've had my 2000 plate IS200 from new (3 years company car and then I bought it off the lease firm). Had it serviced by local Lexus garage till about 5 years ago. Only done 130K so definitely serviced by Lexus at 60K. Engine Management light came on few weeks ago, local (non-specialist) garage plugged it in, showed P1346, possible camshaft position issue. Advised me to check when the cam belt was last replaced. Checked my Lexus garage paperwork and couldn't find any mention of it being replaced. Tried calling them to check but they only keep service records for 2 years (!).
So called my local independent specialist (UK Tecknics in Maidenhead) and took it over there and here's the state of mine... seems likely it's never been replaced
Eeek!
I've left it with them to replace...
Thanks for the pinned post here otherwise I would not have realised how serious this could be.