Water on front driver floor board

[mjquillici]

We've been having some freak rain storms lately, and today I went out to drive my 240D and there was water on the floor board, and the carpet was wet. It also appeared that there was pooled water where the windshield meets the dash. Is it common for the windshield seal to rot out and allow water into the car? Also, is it possible to have the seal replaced without replacing the windshield??