I know its a bit delayed, but I got mine done at Tommy's Window tinting on SE 12th @ Belmont I believe. They did a good job, tinted all of the panes of glass to the legal limit. I don't recall the price now, but seemed the same as anyone else. They also do the tinting for Broadway Toyota.
Check out the Portland Window Tinting company, Window Tint King in SE Portland Oregon. Their website can be found by going to Google and typing the search phrase " Portland Window tinting" and you can get a free online quote and answers to tint questions.
I don't remember the tint level, but the Prius cannot legally have darker windows on the back than the front. Apparently passenger cars can't have any windows darker than the legal limit that applies to the front windows...of course if you pushed the size out, called it an SUV you could tint the back as dark as you want. Google had the answer: Oregon Window Tint Law - TintCenter.com
