I own a 2003 Accord LX 4-door. After last week's heavy rains here, the footwells in front of both rear seats both filled with water. There was no obvious signs of water entering the vehicle, everything on the floor forward of that was dry, as were the seats and headliner. The insides of the windows were all dry, and the rear door seals all appear to be in good condition, ie no tears or obvious damage. I did not find any obvious water on any of the interior door or trim panels. The driveway is inclined, the car sits nose high when parked.

The body seals on both front doors have been replaced twice because the doors chafe holes in them, but it doesn't look like there's any water coming in from there.

Has anyone else had this problem? Any ideas on where to look for leaks would be appreciated.

 

Does this happen with or without driving around in the rain?

If it happens only after actually driving around in the rain, check the floorpan for drain hole plugs. Look on the underside for holes, with the plastic plug missing or somehow messed up. I don't know if any of these are hidden by components, so if no luck, you may have to remove seats & carpeting (PITA!!) & search again.

There's actually tons of holes thru the floorpan, for things like exhaust heatshield mounting bolts. Some are just for drainage during manufacturing. None of them should be open any more, whether they're filled with the proper mounting bolt or closed with a plastic plug.

I think(?) the LX doesn't have a sunroof; otherwise I'd say check the sunroof drain tubes.