what are the laws on OC in a motor vehicle
In Michigan the law considers a gun in a vehicle as "concealed" and a CPL is required to have a pistol in a vehicle (unless unloaded and in a case in the trunk or inaccessible to the occupants for transport).
As far as the law is concerned it doesn't matter if the pistol is in plain sight sitting on the front seat... by virtue of the gun being
in the vehicle it is considered concealed because this portion of the law isn't concerned about whether the gun can be seen... but whether the gun is in a vehicle... seen or not.
Sad to say I've not bookmarked the applicable MCL's to give you as a cite to research... I hope someone will show up with those momentarily.
But the important thing is.... in Michigan there is no such thing as OC in a vehicle... if the gun is in the vehicle it is considered "concealed" by the law.