With the coming of Spring, I've popped the hardtop off my 90 500SL, and cleaned up the softop.....I actually have better water tightness at the "A" pillars, and experience no leakage at the seal of the windows and top at the A pillar (a problem I DID experience with the hardtop in place!) Now a new problem: after driving at highway speed in rain for about two hours, I got off the turnpike and immediately experienced a new "gremlin", at stop and go speeds. The passenger seat back began assuming an upright position, and when readjusted by the control on the passenger door, immediately continued to "self-adjust" to a full upright and forward seat position.......upon investigation, the rear foot well behind the passenger seat had visible standing water. Once sponged out, things appeared normal, although I did find one wire with plastic connector beneath the rear edge of the passenger seat which was connected to nothing. I assumed it may have gotten water into it, shorting the circuit and activating the seat adjuster motors......Next morning, again drove for an hour, in very light mist/rain.....and at journeys end, had same symptom.....self adjusting seat.....but now the controls have no effect other than a "clickling" of solenoid sound in the seat....they won't move......Please help.....

I would definitely take out the seat and clean all connections underneath the seat. Check all electronic components as well...since water will do no good to the long lasting endurance of these components...
Try to find the cause of the water-leaking problem.

greetingz,

Better than a sponge
 

For getting water out of the floor of my car I use a syphone. It's not that quick but its labor free. And taking advantage of that, as long as its setup and already wet and I have the time to wait, or do something else, I'll add more water to rinse everything out, or maybe even some soap. I had to do this when my daughter threw up in the back seat so I was already commited to wetting and cleaning it. I even setup a garden hose to run as fast as the syphon and just let it rinse itself.

I once parked my 300D on a nice sunny afternoon under a lovely oak tree. I left the sunroof open. I came back to the car to find that a broken sprinkler head was spraying a thick stream of water about 15 feet in the air, and the downfall was CENTERED in the sunroof opening. I measured 4 inches of water in the back floorboards! Driving was a nightmare, especially when I had to hit the brakes and a river flowed through the car. Anyway, I took it to the neighborhood car wash. The vacuums there are wet/dry vacs. Cost a few dollars, but sure did get most of the water out. Good luck!

The bigger question is....
 

....how is the water getting into the rear floor area, and how can I prevent it in the future? Easter Sunday was the first incident, and each day I've attempted to soak up the water, hoping it would dry out. It appears that the water may actually be contained somewhere else, and is slowing and continuosly leaking in and re-filling the floorboard area. Could there be some contained space which filled up and is acting as a reservoir which is slowly emptying into the floorboards? I'm scheduled for a service appointment next Wednesday, but hoped for some possible explanations to help them permanently "fix" the problem, as well as clean it up and get the power seat operating correctly again. What about the rocker panel? It appears to have a rubber drain outlet located almost directly beneath and adjacent to the rear floorboard area. Could it be filling up and spilling into the back floor? And, if so, what is the fix?

I know that a common cause of this in Bimmers is clogged rocker drains. Don't know if this applies to your car but it makes sense.

I vote for clogged drains.
Any drains around the trunk area?
good luck

wrotella,

If the water outlets in your rocker panel are clogged up, you should be able to hear the water flowing through the threshold every time you accelerate and brake. You can check the water outlets in the rocker panels by poking a thin steel pin through the holes in the rubber. If it is clogged up, you should immediately see water coming down...

I have posted on this problem in the SL-section as well.

good luck and greetingz,