Taken from FutureZX5SVT's thread.
Quoted because I have the same issue on my car. It is an intermittent issue that I usually notice only on the first couple of stops after the car has been parked overnight. The sloshing sound seems to come from either under the floor or behind the seats somewhere. I haven't had a chance to really dig into the problem, but the only explanation I can think of is fuel sloshing around in the tank when it reaches a certain level? Can anybody else relate? Thoughts?and the weirdest of all takes some explaining... When you roll to a stop, you can hear liquid slosh back and forth... Could this be the fuel tank? Never been in a car where I was able to hear it so clearly.. [pray]