A very, very thin protective layer. 2-3 weeks, I'd be happy for more than 2-3 hours.
This is the deep glo$$ 3.0, and with a layer of mothers pure carnauba applied the next day after the sealant cured. Beads water great, but I'm not sure that gives much protection against any sort of acid. The etching is definitely in the clear coat. Worth a try, but no dice. The hood already looks worse than my 2000 civic, which is parked right next to the subaru.