Well Easy, here's what I would do (not 100% certain as I would have to try first): I would use the larger decal but cut it in half to remove the writing. It is a nice pictogram and will personalize  your car while sending a message to those in the know, to the inner sanctum. No need to involve anyone else

I like the Ring decal such as Gnil's, it is discreet but has meaning


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Slow In, Fast Out