[aphall]

You don't really need to paint the glass where the spoiler contacts the glass because in order to see the tape underneath the spoiler, you'd have to look up and under the rear glass window. It's hard to see unless someone was actually trying to see how it was attached. I don't have the bubble problem you speak of on my spoiler... and I didn't use glue to attach, just double sided tape and you're good to go.