Went out to see the part 2 filming location first hand yesterday, and what a beautiful area! Gorgeous homes, hilly terrain, and lots of money in that area-- one house even had its own waterfall right in the center of town. A bit of a rich New Yorker's paradise. I stopped at New Preston first and took a photo from where the phone booth stood in 1980, note that most of the same buildings are still standing, one in the back there even the same color thirty years later:
New Preston only has one major road, which is flanked by antique stores. This is the road Max drove his tow truck ("ASSHOLE THIS IS MY TRUCK"), and he turned left at the town hall seen at the top of the hill.
After New Preston I stumbled onto the road they drive up in Jeff's pickup in the following scene, which is at the intersection of 341 and 45 in Warren, CT.
Thanks to information from Campblood.net I found the incredibly remote and isolated lake where the bulk of part 2 was filmed, its called North Spectacle Pond and its a private pond in Kent only accessible by a maze of dirt roads that wind through all these woods. There is a boy's camp there (Kenmont), but it was not the camp they filmed at, I didn't have good enough info to find the real site, but I'm guessing it was down one of the many roads marked "no tresspassing." I did manage to get one shot of the pond:
I think the camp they filmed at was off the left edge of the photo. Next time... I will find it...