My wife had a 99 Corolla when we lived in Oklahoma. The heat pretty much deteriorated some of the finishing tape (stickers to match the interior color) on the inside of the door. We tinted all 4 door windows and the back glass. There was a dramatic change in the interior temperature after the tinting was completed. Check your state laws, but I would say do it.
I've been thinking about getting the windows tinted on my iM. Not so much for the look, but I noticed that seats get really warm on a hot sunny day. Would tint on the windows help with that or would it be a waste of time?