[jakeru]

I have some colored crest valve stem caps that are chrome-plated abs plastic. I wouldn't call them metal. I think they are the OEM style (tequipment), but they came with the car when I bought it, so I'm not 100% certain of that.

That said, I'm not the biggest fan of them, as the way they are designed leaves them sticking out quite a bit. I got a bunch of aftermarket valve stem caps in aluminum and brass and haven't decided on which ones, I think I may run one of the aluminum ones. The plastic ones are lightest, followed by aluminum, then brass as being the heaviest.

I needn't concern myself about TPMS issues because my car is not so equipped, but I suppose it's true that bare aluminum caps might corrode on brass valve stems. Brass caps would not have any issue, but they are the heaviest caps out there.