Thats a different approach but whatever keeps the mositure out ...... go with it...
I used Dynomat over the entire door area then put the door card over. Made for a really nice solid door sound when door shut and kept moisture and noise out.
I covered all of the holes and faced the adhesive towards the inside. Only holes that where needed was for the Door interior handle and window crank. Covered rest of inside of door which door panel covered. Hope that make sense.If you don't mind me asking, did you cover all the holes with the dynamat and did you put the adhesive side facing inside or to the outside of the door skin?
I use the same six mil clear plastic but I attach it just like GM did. Buy a box of 3M Strip-Calk and run it around in the original slot. Initially cut your plastic a little over-sized and stick it to the calk. Trim for the window crank handle & door handle. Trim the bottom to tuck in the lower slot in the door. Then just trim about a 1/2" beyond the strip chalk. After the first one, you'll find yourself able to make these relatively quickly. And it's so clean, you would have no shame removing the door panels in a big car guy crowd.I used 6 mill clear plastic like your thinking ,but used strips of velcro to attach to door, working so far. both from local ace hardware store
It not only keeps moisture out, it also substantially reduces interior noise. You will be amazed at how much wind noise they eliminate. They also make your heater/AC more efficient.do you still need that "barrier" if the car does not see the rain?