Keep driving. Go elsewhere. We purchased a certified 2013 450GL. The car is fine: it's a Mercedes. Find another dealer though. The salesperson's description of the warranty has been wrong now twice. In addition, the salesman assured us that all four tires were brand new. After 8 thousand miles the back tires are shot, and the front ones have less than one thousand miles of tred left.
A close look at the paperwork reveals that only the back tires were labeled "new." Even then, the service manager asserts that "new" doesn't mean they were actually new. She also asserts that "cars go through tires in 8 thousand miles, that's not my problem."
Excuse me? This is the level of service I received in my younger years when I bought cars from used car dealers.
So don't even pull into the dealership. Find another. They are out there.
PS: looking at the other six Yelp reviews, I see all with 5 stars. Really? I'm wondering now about Yelp's integrity.