Sorry you got insulted, but diesel hybrid "cars" are at least 5 years away from California. They are too costly to build, and thus are only available in fleet buses and large trucks, where cost can be absorbed by the fleet experience.

And regardless of what tricks and filters are used, diesel is inherently dirtier than gasoline. That will not change, ever, never ever. Did I mention "Never?"

And additionally, diesel has HUGE hurdles to overcome before USA will accept it as a viable alternative.

If you think gasoline Hybrids have "taken off slowly," you just wait and see how slowly the first diesel Hybrids take off.

Something that would help immensely is if companies other than VW (bad reliability reputation) and Mercedes (too expensive for most people) start to offer USA diesel sedans.