Hi Ian,
I have a SC430 2005 and also have the tyre pressure warning light staying on, no buzzer.
My car has been fitted with non-runflat tyres for a few years now without problems.
I have noticed that on the O/S/F and N/S/R the wheels have the aluminium vales as per Lexus and on the N/S/F and O/S/R look like standard rubber valves.
I've not had the warning light illuminated before so can't really see this being my actual problem.
I would also like to know how to turn off the warning light.
Regards, Mick
