From an old post of mine:
I had real success with buying from:
www.ledtrailerlights.com
Pull out the old bulb pop in the new. I did not detect a polarity issue. DW was very happy. Have only used them 1 weekend (dry camping) but so far so good.
We like the color. Warm white. Bright or brighter then the incandescent ones I took out. (921's)
Replaced only inside bulbs, except over stove (too hot I thought), and the long fluorescent fixtures. The vanity ones were a different base. (1141's I think)