You are doing a great job. I just did a 79 Lincoln Cartier edition. Car had two year old hardened sap all over the roof, trunk and hood. Knowing what the guy wanted to spend I didn't go so far as to do the swirls but he left with a smile on his face so I guess he was happy. Apparently the car sat under a couple of pine trees for a year before he moved it to his house.
I had to use gas to get the sap off. The interior had an entire lawn bag full of trash, I've never seen such disrespect for a car.