That's nothing compared to the number of cars I see on motorways with (I presume) underfloor panels flapping in the breeze. Surely the occupants can hear them rattling away?

The seals on the door on these models are stuck on and are a well known problem. Ford will happily sell you new seals at a price, but most people just use glue or double sided tape to stick them back on. I have done several areas on my doors.

Hope that helps

Our Mk1 Focus had about five tiny plastic grommets embedded in the black rubber strip which popped into tiny round holes along the bottom of the doors. It was worth pulling them off every so often because they concealed a metal seam over which a thin strip of sealant had been applied. A decade of slammed doors had resulted in (presumably) microcracks allowing rust to develop along the seam under the strip. If this is neglected it will rapidly (and invisibly) eat away the bottom of the door.