Totally random question nintendo ds?

Im getting a nintendo ds here soon . I really want to put a cute detail on the outside to make it more mine. I searched for small car decals, thinking those would be the most durable....however, not only am I having trouble finding one small enough, I cant find one similar to my tastes. So, would it be ok if I placed a cute sticker on the outside, and covered it with a clear nail polish to prevent fading, and wear?