have you lost power at all, if so maybe a box got blown out but its unlikely.
probably just got some water on it somewhere and its the water evaporating, i wouldn't worry about it.
Mabe the breather of the fueltank is partly blocked.
Try opening the filler cap while it is hissing. When the pressure escapes and the sound is gone, cut your pulse or get the KY.
Hey , dunno what car you have , but My Dad's and Mom's 323i e90's both do it after spirited driving . They just tick afterwards . No idea but I think its normal