I'm sorry I didn't check this posting sooner, and I really don't know if this would have been any help, but when it comes to pine sap - and I know you said it was overspray that only 'looked' like pine sap - I use RainX. RainX dissolves pine sap on contact. I couldn't help wondering if it would have taken off the overspray as well. I use RainX on the paint as well as the glass and cladding, then wipe thoroughly afterwards...for pine sap.
Return evil for evil to no one...as far as it depends upon YOU, be peaceable with all men. Romans 12:17, 18