Had my IS since November last year and purchased the Lexus extended warranty for 24 months in January. Not had cause to claim as yet. In fact, if I don't make a claim during the 2 years, then I'll be very happy. Peace of mind.
I considered the RAC warranty at half the Lexus £800 cost, but struggled to work out from the policy document if anything was covered ?
As I say, I've yet to test the Lexus warranty, but it does seem very comprehensive.
I'm likely to move my IS on next July and it will still have six months transferrable warranty.
Up against a similar spec/mileage car, bet I sell mine first....and at a premium !!