I would use a strong traffic film remover first. Something like crudzilla from dodo is good however this will strip previous wax layers if your polishing and then protecting with wax that's no problem tho. Otherwise something like auto finesse citrus power is good and that is wax safe. Supernatural tar and glue remover is also a good citrus based cleaner I have also heard but never used valet pro citrus pre wash is good and often added in a snow foam for a bit of extra kick. Spray on allow them to dwell for a bit then rinse off. The stronger they are just be careful how long you leave them.