The cam belt change is not 10 years. Its 100,000 miles that's what Lexus recommended but its not always what Lexus dealers will indicate.
There is no reason whatsoever to change a cam belt after 10 years if it has done less than say 60,000 miles.
They wear on use they dont deteriorate by standing still in these time frames.
The maintainence schedule for Lexus indicates a change only on mileage (100,000 miles) and not on any time frame.,
Not sure about that. Is the SC timing belt made from some special material that doesn't deteriorate?
My service book for my IS also says 100k no indication of time. But I asked Lexus and they said 10 years, change it, as it does deteriorate over time.