The fact that both were damaged certainly explains why your reception is so poor. Did you do the tint yourself, or is there some sort of recourse with a shop? The eBay antenna shows it'* primarily tuned for FM signals and won't help much if you listen to AM. The other problem is connecting it to the antenna module. Connecting it directly into the back of the radio may be a possibility, but an adapter might be required.
I'm surprised about the front antenna. It is supposed to be located between the layers of glass and should be fairly difficult to damage. Do you have the original windshield?
You may want to talk with some glass and/or tinting shops. I'm sure these must get damaged from time to time. There may be replacement aftermarket applique antennas available. I've never looked into this, but it may be worth some hunting around.
StingRay Bike w/cards in the spokes, Weeeeeee!