The answer to your question is....it depends.
It depends on whether you have a CPL or not. Without a CPL a sports arena parking lot
IS indeed a PFZ, with a CPL it is
NOT.
750.234dWithout a CPL that is the law you will reference to determine the PFZs that apply to you.
(1) Except as provided in subsection (2), a person shall not possess a firearm on the premises of any of the following:
. . .
(e) A sports arena.
. . .
(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.
(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.
I've included the reference for entities licensed to sell alcohol because that may also prevent you carrying through their parking lot sans CPL. Notice the bolded portion that exempts a CPL holder so if you have one you are good to go.
Bear in mind that the above law does NOT have a parking lot exemption nor does it have a max seating capacity prohibition. Both of those are found in CONCEALED carry PFZs law
28.425o, but if you are openly carrying your pistol that law will not apply to you.
Bronson