I religiously use a Road Angel Professional Connected to retain my licence!
My first IS-F went for 20,000 miles of painless driving over 18 months, needed 2 front tyres after 10,000 miles due to incorrect camber settings...Lexus Chester thought the car was poorly set-up, but still charged me £400 for a new pair of Potenzas...tyres were worn on inner edge only so not easy to spot (and I certainly was not keeping an eye on the tread depth at such low mileage - Evo mag ran their longterm IS-F for 18,000 miles before changing tyres, and I am sure they drive sideways more than I do).
On the extended warranty front, how certain are you that you will categorically still own the car throughout this term?! Will you simply be buying the warranty for the next owner?