A door seal is one of those things that you don't realize how much you will miss it until it is gone. The door seal makes closing the door easier and the tightening the old between the old and the body. The seal is also very important in muting the wind noise and the keeping and out the rain. Beyond that a missing door seal is a terrible annoyance making it difficult to close the door properly, hanging down to block your ingress or egress, or just looking bad. They are almost always made of rubber and often become hard over time or they breakdown and disintegrate. They are usually held in place by pins or by glue both of which can cause them to sag down or come off the door. They are sometimes referred to as door rubbers or door weatherstripping. An additional problem is trouble keeping the interior cool with the AC or warm with the heater if these go bad.
Door seals should remain soft and supple. If you squeeze the seal, it should puff back up. Hard seals or those that collapse like mush are not able to form a proper seal and may leak in water. It may also cause air leaks which may range from an uncomfortable draft to an irritating eye-piercing whistle. The door weatherstrip has been around as long as there were enclosed cars. Any time metal is meeting another piece of metal, a piece of rubber needs to be there to cushion the impact and create a firm seal.
Changing the door seals in your car can be an easy do-it-yourself experience but like most auto repairs it may be best to allow a qualified mechanic to change them out. Please see the guide instructions below.