I did my 87 cougar myself years ago. The defroster never worked and the window was so small I just took a razor to the defroster lines before I applied the tint. It took everything right off and the tint went on perfect
So if you don't care about your defroster, that is always an option.
But realistically, if they gaurantee the install for life and you are not happy with it, tell them to do it over, and if they say it will just happen again, propose putting down more money for better tint, or tell them you want all your money back. You shouldn't pay big bucks for tint and end up with bubbles. That's just not right.

But realistically, if they gaurantee the install for life and you are not happy with it, tell them to do it over, and if they say it will just happen again, propose putting down more money for better tint, or tell them you want all your money back. You shouldn't pay big bucks for tint and end up with bubbles. That's just not right.