One of the 1st things I always do to a car is get the windows done, as it makes a world of difference in my opinion.
pros: like above makes the car look so much better, imo. supposedly keeps the car cooler in summer, I cant comment on that as bein from Scotland we dont get summer.
also added privacy if u have valuables lying aroung in the car.
Cons: unwanted attention from the police if u get the front windows done noticably.
As brett mentioned I have heard of ppl gettin white lines round the rear heated screen, I had them when I picked the car up and guy says they would gradually disappear, 48hours later, not a white mark to be seen. if in doubt ask.
I got the darkest tint on the back (due to the misses havin a habbit of leavin laptops etc lying. and the lightest on the front, and have never had any unwanted attention.
pic of the back window a day after they had been done, as u can see the white line has more or less vanished.