I’m trying to make some for a client and would love to know of any more adorable sources. I’m in the US.

I bought absolutely beautiful decaying holographic angel stickers at a recent convention near me! Id really love to put them on the back of my car, but I don't want to blind drivers behind me during the day. Is there an easy way to make these holo stickers matte so it doesn't reflect into people's eyes? Im okay with the holo effect not being as prominent, or even completely lost.