You're driving an inline 6 twin turbo not a 2.0L 4 cylinder. The old saying is what, the more moving parts you have the more chances something goes wrong?
The HPFP is covered to 120k now, the wastegates to 82k, I believe the injectors are covered now as well(if anyone could confirm this). Most of these extended warranties came out before most people reached the 4 year/50k mark. Unless of course you drive 25k+ miles a year.
Valve cover gaskets go out on every car, these engines run very hot and thus compromise the integrity of the gasket much sooner, especially the area where the turbos are located. A rubber gasket is a rubber gasket, I don't really know what you can do to make these last longer other then redesigning the entire engine, which would take away the entire point of me owning this vehicle.
Some people are going to have bad luck with their cars, it's just a fact, and it's the same whether you buy American, German, Japanese, or Korean. If you want a BMW that you just want to be seen in then drive a 328, much simpler engine with a lot fewer moving parts to go wrong.
I came from a DSM, so I guess some of this stuff doesn't even seem like a big deal to me. That car was basically a perfect engine block surrounded by half-assed garbage parts, Japanese parts as well, so this theory that the Japanese create these perfect vehicles is hilarious. Anything Japanese that includes a turbo has just as many issues as a 335i does.