I put 20% up front in Mass and I have never had an issue with inspections or police. It matches the back really well my wife likes it because she can watch people and they have no idea. She thought it was too dark until one day we were parked next a car where this kid was picking his nose and popping his zits and he had no idea she was there. The look on his face was pricless.
I paid $80 and have a lifetime warranty. That is the part when you need to go to a shop that will be around for a while. I had a couple offers from "nomad" installers that went from shop to shop doing it, but who do you call if there is an issue? Spend the little extra and get it done right. Bad tint looks REALLY bad!