I didn't do the roof. I figured most of the noise and heat would come directly from underneath me. I guess I could still go back and do the roof, but I am happy with the results.
I used two of the large cases of Dynamat Extreme for the interior, not counting the doors which required an extra 15 linear feet. Made a huge difference in sound and heat. But, at $150 a case, I have close to 400 bucks invested.