I agree with what everyone else is telling you. Go with the 3.8 Supercharged. But, make the investment and puchase a carfax account.
this will save you a lot of headaches in the future and can answer a lot
of questions for you. WELL MAINTAINED IS THE KEY. I didn't know about
the all purpose coolant. Sounds like a good idea.
I may have found a MC SS Supercharged in my neck of the woods ( Arkansas ). It has "Ebony" interior but I like the exterior color.
There are several Black/Black SS's out there. Just be selective. Get what
you want. Watch out for Northern cars NOT garaged.
RD.