Replying to Window tint delema

Fist of all I live in NY where 705 tint is legal but in my smallish town cops have better things to worry about. I have a 2002 Pontiac sunfire and was looking into ordering some precut tint online for the side and rear windows from snap tint. The only problem is putting tint on the inside of the rear windshield will be near impossible due to lack of space between it and the speaker rack thingy. Could i just put it on the exterior or will the tint decay and become ruined? Does exterior tint even exist? Any tips for putting it on the inside would be great.  Oh and any advice or stories about tint in NY would be great too. Thanks!