So let's skip to sub. (4) and see what the exceptions are, shall we?
(a) Subsections (2) and (3) do not apply to any of the following who, in the line of duty, place, possess, transport, load or discharge a firearm in, on or from a vehicle, motorboat or aircraft or discharge a firearm from or across a highway or within 50 feet of the center of a roadway:
2. A member of the U.S. armed forces.
3. A member of the national guard.
4. A private security person who meets all of the following requirements:
a. He or she holds either a private detective license issued under s. 440.26 (2) (a) 2. or a private security permit issued under s. 440.26 (5).
b. He or she holds a certificate of proficiency to carry a firearm issued by the department of regulation and licensing.
My question would be what 'certificate of proficiency' is referred to. Does WI issue such?
Yes they do, but until receiving that certificate OC in a car or boat is illegal, unless you are an exception as stated above.
In other states does even having a CCP allow you to carry a loaded pistol in a running/moving vehicle? A LOT of folks seem to think it does.