To check your seals you can cut a 1" wide strip off a thick plastic trash bag, about 1 foot long, and use it as a "feeler" all around the door seal. Just place the strip of plastic between the door and doorframe, close the door and see how difficult it is to pull the strip out. If it slips right through, you've found a possible leak.
If the rubber seal isn't torn and is stil somewhat pliable, you can sometimes insert a thin layer of weather stripping behind the seal to get a good seal again. I've done this a number of times, and it worked well most of the time, but sometimes not.
In other cases, I've had to unbolt and re-adjust the door to get a good seal. A fender bender can throw things off but you are usually able to see body panel to door alignment problems.
You might try spraying the door seams down with a spray hose and then look for the trail of water before it reached the floor.
JM2c.
-Jorns