I would say it would likely fade if it is not UV stabilized ink. I would recommend putting a clear UV film over the decal too.

I would also be very very very careful putting it on in a completely dust free area. Even if you get every grain of dirt off your hood, the sticker might pick up a grain when you peel off the back and then when you stick it on, there's this tiny bump under the sticker that looks terrible - especially if the sticker is glossy. (I've been there) Try to avoid sharp square angles too, as these would peel up over time on a large sticker like that - try to round them out a bit.

I think the idea is cool, but I would go for a rad symbol with a circle or triangle border around it..

Post pics if you do it!