My 2009 g37 decelerated to a bout 10 mph from 30.I parked it.Looking under the hood there's green fluid splashes around of engine.I am not a mechanic.So could anyone tell me what I am in for as far cost and if I should take it to the Infiniti dealership or a local garage mechanic?

I had the car taken to a garage,who I told the mechanic over the phone,what happen and that was antifreeze splash on front engine.Today he calls me back saying they drove the car to test the transmission but the car over heated and had to bring a couple of gallons of water to get it going.He claims I never told him of the leak up front of engine.So he is replacing a split hose and I haven't heard back from him yet,it's been a couple of hours.If he cause damage,how much am I going to have to fight to get him to admit fault,and repair it?

From what I said above,what are the chances they will repair any damage they did. By driving it?

Did you ever get this resolved?

With aluminum heads it depends on how hot and how long it's driven before one gets warped and you lose a head gasket. Honestly I would take the car to a different mechanic if they didn't bother popping the hood before taking the car for a test drive.