Infiniti G35 Engine Revs Up

When I Start The Car, The Rpms Goes Up Like I’m Giving It Gas. It Also Has A Vibration That Is Felt Where Your Feet Go.

I Bought A G53 Yesterday. The Car Cruises At 2900 Rpms At 70 Mpg. This Seems Too High And Will It Affect The Gas Mileage??

To Make This Short I Have An Annoying Rattling In My G35. When I Take Off In First My Car Rattles Until I Hit About 3k Rpm. It Does It As...