First, Welcome to the board!
Being that Michigan is a "shall issue" state, there is only the issue of age and felony keeping someone from getting a CPL. My view is if you can legally purchase/own a firearm you should certainly be able to get a CPL. Some argue that even someone with a felony on their record should be able to OC/CC/have a CPL. I have not made up my mind on that one yet.
As far as "OC in your car" I think it should be understood that OC is considered "in 'plain view' of the casual observer" so to speak. If you enter a vehicle the firearm is no longer in plain view of anyone outside, so it is deemed concealed. If you are out and about and you walk behind a tree it is not concealed, just obscured. If we had to worry about our firearms being obscurred by this or that while going about our business what a nightmare that would be! You would have to make sure EVERYONE sees your gun purposely at all times! Try walking around sideways with your strongeside hip pointed at the general public, that wouldn't be any fun...or would it..? I think the definitions usually rely on the "reasonable man" view.
Personally, if you can legally own a firearm you should be able to carry it anyway you want, anywhere you want. Go figure, right?
Again, welcome to the board!