IMO Armor All will destroy your car. Look for water based products with UV protectant in them.
These spots your talking about, are they water spots? If so there are tons of products out there to remove hard water spots from boats.
Here are a few of my favorite products
Babes Boats Spot Solver
Boat Bling's Hot Sauce
Follow this up with a great protectant.
303 Aerospace Protectant