Very cool idea and nicely executed! I agree with woodsac on the frame center position of the door though, particularly on the second image Id like to see that image with some of the sky cropped out, putting the door in the top third (or so) of the frame.
I think this is a great idea as well. But the question of the day as stated before is do you carry this door with you in all of your travels. If you do I hope you don’t cart it around on top of a Honda or Pinto or something like that. Great work!