Same deal here Art.. not overly enforced these days pending who the building inspector is, but generally the wall between garage and house is supposed to be 5/8 drywall vs 1/2. At one time, and possibly still some places, it's supposed to be double layer drywall with no overlapping seams.
With todays cars... that turn themselves and their electrical system on and off at will... I'd be doing my utmost to have as sealed a garage as I could from the living quarters.