I've been reading this thread and a bit surprise to find out a couple things like:
A.) Didn't know there are a few people in the car business here. I too am in the car business, 20+ years and currently work for a Maserati dealer
B.) Shocked by fellow colleagues that believe the OP should just lay down and chalk it up as a learning experience.
C.) If the email from Maserati is real, I'm really shocked because as a former car manufacturer exec (not Maserati) and especially on a car that's CPO'd, this is not normal practice regardless if the dealer is private or not.
I guess we're all entitled to our own opinions and our beliefs.
In California there are laws against such practices and I'm sure these laws pertain to other states as well but this is easily settled by obtaining a lawyer which I'm glad the OP has done.
Now, regarding Carfax and I'm not defending the dealership here so please don't insinuate otherwise however sometimes Carfax takes a while to report things on their end. I remember a few years ago I was going to purchase a used Lotus from a client who had indicated the car had been in an accident where insurance was involved and that the incident happened a few years ago but when I pulled the Carfax report, nothing and it wasn't the first time I experienced this but again, I'm not saying this is the case with this dealer.
Anyways, hope all gets resolved soon enough.