i think any bug and tar remover would work, your best shot is puttig the product on the top of the sap, and letting it soak. i would be weary of getting any tar remover on your paint and letting it soak for long periods, as it may stain your clear. I have never seen that happen, however anything strong enough to remove sap should not be left on your paint for long periods of time.
so if you dab it on the sap and remove it layer after layer, eventuallty you will have no sap left. i would use a paint cleaner to get rid of any microscopic remians and chemical tar remover left over, and then repolish and top with whatever lsp you use . . .