My last 2 cars had the little ad inserted down there, too. As a matter of fact, one of the ways I found out who the dealer used to tint their cars was to drop by there and look at the windows. That way I didn't pay twice the price at the dealer.
A bit annoyed by my tint guys! They places a small "ad" inside the film on the driver's side window (on the bottom). Pretty sure I should get it for free if I'm advertising for them! I'm just saying!
That's always been my philosophy. That's why I tell the dealers not to put their names on the car - I refuse to advertise for them for free. As far as that ad on the tint is concerned, I would go back to them if it's that noticeable. The business that tinted my G did have it's name on the tint in one place, but it was so inconspicuous that I forgot about it. I had them do the Q, and their name is nowhere on the car. However, I did just check, and noticed that the glass manufacturer's name and information(AGC Automotive) is on almost all the panes of glass. Again, I hadn't noticed until I just checked. Chick, good luck at the tinter. If the name is in just one place, maybe they'll replace that one piece.