that STINKS! You so did not deserve this and I am so sorry it all happened to you. Grrr!
Make an effigy of the new boss and, with a drink in hand, though the boot at it repeatedly!
Think of stupid/witty things to say to the irate lady like: "Well, if you car wasn't so big and gas guzzling it's would not be so tempting to scratch, now would it???" or "Well, it's just a scratch, I was going to do a whole mural!" or "AGGGG! Don't get crazy on me, Lady, you don't KNOW CRAZY! I can do CRAZY!" and then balance your coffee/water on your head and sing the national anthem while waving your arms around. That should do it.
You know, fun things like that!
Plan your amazing escape when you get your new job: like the flight attendant from Jet Blue who took some beers and popped the emergency escape slide to make a break for it.
I will add, seriously: things seem to come in threes. You have had your three, it feels like. Decide that this is over and once you are though this it will be better. (I have had three really cruddy things happen and I am focusing on this philosophy right now!)
Good luck, I am so sorry and that JUST STINKS!