Sloshing

[oceantools]

I keep hearing a "sloshing" noise behind me, slightly to the left. I'm presuming this is the fuel tank....? Anyone else experienced this?

[Knights of Aston]

Could be the fuel tank. Which model is it (volante or coupe)? As the amount of stuff between you and the tank is different.
Also could be rain water in the sill. No big deal if it is as they're alloy and won't rust. Usually caused by a blocked drain cover. Can be 'unblocked' by your local dealer if it is.