I’ve Done This Exact Job.
A Friendly, Neighboorhood Auto Glass Business Should Help You. The One In My Area Will Sell DIYers Butyl Sealer (1/4" I Believe) By The Foot, Very Reasonably.
Thoroughly clean the plastic and the contact area on the door, using denatured alcohol (Wal-Mart, Hardware Store, Etcetera). Then peel the butyl “ribbon or rope” from its backing and apply it around the perimeter. Finish by pressing the plastic into place. The butyl remains soft and sticky and usually allows for removal and reattachment of the water barrier, just as you wish.
Auto glass companies replace lots of door glass and keep rolls of this material on hand.
CSA