The decals should hold up fine there. The only problem is if you go through automatic car washes, the brushes could catch and edge of the decal and start to peel it. That's the only real concern. Beyond that, they hold up just fine through the winters.
Do you have a color scheme going on? Chrome would be nice or even carbon fiber. Reflective light silver can look very white (it's really reflective white), just just be aware of that. Maybe even we could do something with a chrome background/border and silver foreground. That would give it some dimension. There is the option of doming these as well.
Let me know what you think and we'll make something work for ya.
