I can get 15% black tint with metallic in it, or I can get 5% black tint, but no metallic in it. The metallic tint will help to block out more sun and keep my leather protected better from fade, however it won't be as dark as the 5% tint and I believe you can still see into the car with 15% tint. I would prefer to not have people be able to see in, but I am also concerned with too much sun and UV getting in with no metallic. What would you do? Is 15% dark enough so people can't see in?