It could need 1 of 2 things mate a good machine polish or worse case a wet flat and polish back. This time of year is the worst as all berries are ripe and very acidy and when it lands on paintwork it doesnt take long to burn through the laquer.
Sadly, worst case is the clearcoat is through or there's insufficient build to support flatting back. Had this on a Golf a month or so ago. A sprayed repair is then the only option.