I've had my decals on for about 3 months and they are holding up great!
Here's what I did:
1. washed and dried the cladding with good soap (meguiars)
2. wiped the cladding with rubbing alcohol.
3. used a hair dryer to warm up surface (this probably isn't necessary now, but it was kind of cold (March) when I put the decals on and they didn't want to stick very well)
4. applied the decals and rubbed for a couple of minutes to make sure they were set.
That's it. I wash the av once a week and not one letter is peeling (knock on wood)
One more thing: I found it was easier to apply the letters when I cut them into individual letters. When I tried to put it on in one piece like a bumper sticker, it was hard to line up and the letters didn't match the cladding exactly.
I'm really happy with the way they look and really add to the appearance.

Go for it, you'll be glad you did.

Good Luck!
