Any one ever hear that sound like water as a back seat and does that happen while parking at an angle while it's raining like up or down hill and will it flow out no problem or that should never happen to a car only 10 months old I have herd of this before haven't seen it yet on an S and what can I do to get at it to get it out cause If I could see it I have shop vacs but i got to the bitten of the trunk and there was nothing wet???? Thanks in advance for any answers you guys may have

 

drill some drain holes in your floor

just kidding did you check the spare tire area and the area where the top folds into?

also i'd shinzu the seals for good measure

 

 

you sure you werent hearing the gasoline swish around in the tank??