I have a 335d that was purchased in California as well. If you read the actual fine print on the california emissions law its pretty gasoline oriented. It covers only some things and I'm aware having had my tank replaced as well does not cover the SCR tank, Carbon Build Up, and I want to say a few other items. I'd have to look. But basically the warranty only covers what is expressly listed in the California guidelines.

The SCR tank temperature sensors die all the time on BMW diesels, so its a very common problem. I would say they seem to last about 50-70k on average.

On my diesel I've had 4x EGR coolers Replaced, 3x EGR valves replaced, 4x MAF Sensors, 4x Exhaust Pressure Sensors, 1x DPF, 1x Vaccum Lines, 1x SCR meetering device, 1x SCR tank, 2x 02 Sensors and I have 53K miles :-(

You think the N62's are bad for all of their failures....