Sorry to hear it's been such a hassle. You should mail a copy of your post to the PO and let him know what's going on and you're expecting some accountability on his part.
I've read/heard of cases where the previous owner was sued in small claims court for misrepresentation of the condition of their vehicle. You could go that route based on how he advertised the car (excellent condition, runs great etc.), if someone was present when he answered your questions, or even maybe Bret Anderson's opinion.
Regardless, you have good reasons to be pissed.