My IS220d started to seriously go wrong at about 70,000 miles. I sold it (dumped it back with Lexus) at 140,000 miles when the diff went. It was the final straw having had am almost replacement engine and 3 head gaskets go, not to mention countless other problems. As a rough estimate the cost of maintenance and repair was almost what I paid for the car brand new.
Worst car I ever bought. And it was 100% dealer services with FSH.
Got a nice new Peugeot RCZ now which does 50 MPG, looks amazing and drives way better than the IS220d ever did.