I am not expert on the law, but I think you are correct. Do not expect the law to be logical. However, I would not choose to be a test case.
Keep in mind that the instant you get in a car, a firearm is considered to be concealed even if it is on the dash in full sight.
I admit that what I have been taught does not always jibe with what I read.
http://www.legislature.mi.gov/documents/publications/firearms.pdf
750.234d Possession of firearm on certain premises prohibited; applicability; violation as misdemeanor; penalty.
Sec. 234d.
(1) Except as provided in subsection (2), a person shall not possess a firearm on the premises of any of the following:
(a) A depository financial institution or a subsidiary or affiliate of a depository financial institution.
(b) A church or other house of religious worship.
(c) A court.
(d) A theatre.
(e) A sports arena.
(f) A day care center.
(g) A hospital.
(h) An establishment licensed under the Michigan liquor control act, Act No. 8 of the Public Acts of the Extra Session of 1933, being sections 436.1 to 436.58 of the Michigan Compiled Laws.
(2) This section does not apply to any of the following:
(a) A person who owns, or is employed by or contracted by, an entity described in subsection (1) if the possession of that firearm is to provide security services for that entity.
(b) A peace officer.
Page 150:
(c) A person licensed by this state or another state to carry a concealed weapon.
(d) A person who possesses a firearm on the premises of an entity described in subsection (1) if that possession is with the permission of the owner or an agent of the owner of that entity.