Here is a section I found in the law that looks like it might be what you're looking for. I would say you had it on the ground, not on the car but i'm not a lawyer or LEO. I stand by my statement to at least consult a lawyer for advice on this one and stop posting about it on the internet
Environmental Conservation Law § 11-0901
§ 11-0931. Prohibitions on the use and possession of firearms.
1. ...
2. No firearm except a pistol or revolver shall be carried or
possessed
in or on a motor vehicle unless it is unloaded in both the
chamber and the magazine, except that a loaded firearm which may be
legally used for taking migratory game birds may be carried or possessed
in a motorboat while being legally used in hunting migratory game birds,
and no person except a law enforcement officer in the performance of his
official duties shall, while in or on a motor vehicle, use a jacklight,
spotlight or other artificial light upon lands inhabited by deer if he
is in possession or is accompanied by a person who is in possession, at
the time of such use, of a longbow, crossbow or a firearm of any kind
except a pistol or revolver, unless such longbow is unstrung or such
firearm is taken down or securely fastened in a case or locked in the
trunk of the vehicle. For purposes of this subdivision, motor vehicle
shall mean every vehicle or other device operated by any power other
than muscle power, and which shall include but not be limited to
automobiles, trucks, motorcycles, tractors, trailers and motorboats,
snowmobiles and snowtravelers, whether operated on or off public
highways. Notwithstanding the provisions of this subdivision, the
department may issue a permit to any person who is non-ambulatory,
except with the use of a mechanized aid, to possess a loaded firearm in
or on a motor vehicle as defined in this section, subject to such
restrictions as the department may deem necessary in the interest of
public safety, and for a fee of five dollars. Nothing in this section
permits the possession of a pistol or a revolver contrary to the penal
law.