Can someone clarify this law for me? (Michigan)

I know not to take legal advice from reddit. what i'm mostly looking for is clarification on the wording of current laws, i guess.My work place does not allow firearms. i am not trying to dispute this, nor am i trying to carry while at work. what i'm wondering is, while in michigan, does a private company have the ability to prohibit me keeping a firearm in my car so long as i have a valid CCW? the car is in their parking lot. i THINK this is the current law? but maybe not all of it.http://ift.tt/2hxwvGU, i'm curious as to the law of keeping a concealed firearm (or even one locked up, etc etc) in my personal vehicle, while on the clock (i travel a lot for work) BUT not on company property. IE: on the highway, stopped at chipotle for lunch break, etc. via /r/CCW http://ift.tt/2hnJjwm