I use automotive cleaner/wax, apply and buff with a rotary buffer. The same buffer I use to detail my trucks and cars. If using a true rotary buffer, you would do well to practice first on something not important though, as using a power buffer takes a little learning.
I also have a so called random orbital buffer, but to be honest, while it's true it's pretty much foolproof to use, it's also not much more than glorified hand buffing with a rag. Opinion only on that....others will say their random orbital is great.
Some folks say you should not wax over the decals, but I do, and so far they are fine. I am "gentle" over them though.