I bought these G4s from the internet at a "cheaper" price to replace my halogens.

They were G4s for my overhead cabin area lights (4).

They lasted about a year then BOOM - failure. Took the 21005-DB (100 Watt Dimmer Switch) apart to see what was happening. I found the internal glass fuse soldered to the board fried. And, its not a fuse you can slide out from the end caps and replace--ughh.

Decided to check the LEDs and sure enough some were toast. Evidently, when they failed internally there was enough to fry the fuse in the dimmer. Found a replacement dimmer on Amazon for $22. I intend to pay a little more for LEDs this time to get better quality and reliability.
Was looking at trying to replace the fuse on the board but I don't have the tools for "board" work. I don't even know the size of that fuse yet. Regardless, I hope you all learn from my experience.