I've been just thinking and assuming Eaton St. has some significance. There is quite a bit around the area. Funeral home, cemetery, tree service, etc. The first thing I would think is it's not some place he randomly chose for a stage of his crime. He could either work around there or have visited there multiple times that would cause him to be comfortable with the location in his head.
My idea of a triangle makes more sense if you imagine it the other way around instead. Holly's house -> Eaton St. -> lunch box. Of course we still don't know what, if any, significance Eaton St. has but if he takes her there, switches vehicles or rapes her or disposes of his camo and Holly's belongings or what ever was 2nd on his agenda, and then drives north on 69 it makes a lot more sense. He realizes that he/she left her lunch bag in the back of the car and a piece of duct tape fell off and is on his floor/seat. On the way back to his house or hideout he tosses the two out the window himself as he fears a road block could be ahead and they'd see the two in his car.