You are all forgetting that 30.05 has a part that reads as follows:
(f) It is a defense to prosecution under this section that:
(1) the basis on which entry on the property or land or in the building was forbidden is that entry with a handgun was forbidden; and
(2) the person was carrying a concealed handgun and a license issued under Subchapter H, Chapter 411, Government Code, to carry a concealed handgun of the same category the person was carrying.
So, walk with me here. If you're in your car, and see a 30.06 sign on a parking lot:
-30.06 applies while carrying under CHL
-CHL is an exception to 46.02
-46.02 doesn't apply in your car due to MPA, therefore you are not carrying under CHL, and 30.06 does not apply. You are currently carrying under the exception to 46.02.
So, we fall down to general trespass, 30.05 in this case.
-30.05 says it does not apply if "the basis on which entry on the property or land or in the building was forbidden is that entry with a handgun was forbidden" and
-The person was carrying a concealed handgun and a license issued under Subchapter H, Chapter 411, Government Code, to carry a concealed handgun of the same category the person was carrying.
Note, not under it's AUTHORITY, simply that you are carrying both on your person. That is an important difference. It's the same verbiage that requires you to show your CHL to an officer, even if you're not carrying under it's authority. So therefore, 30.05 doesn't apply in that case either.
Now, 30.05 Will instantly apply if they ask you to leave, or post a sign that you are not allowed, for ANY other reason, but not for the reason of carrying a handgun. Eg, a 'No White Cars' sign, with you driving a white car WOULD apply.
It's a weird situation where there is absolutely no way they can ask you to leave for simply the handgun, because the law does not allow them to.