Sounds like they don’t require probable cause:
(2) Vehicles and their contents
brought into, while on, or being re-
moved from restricted nonpublic areas
are subject to inspection. A promi-
nently displayed sign shall advise in
advance that vehicles and their con-
tents are subject to inspection when
entering the restricted nonpublic area,
while in the confines of the area, or
when leaving the area. Persons enter-
ing these areas who object and refuse
to consent to the inspection of the ve-
hicle, its contents, or both, may be de-
nied entry; after entering the area
without objection, consent shall be im-
plied. A full search of a person and any
vehicle driven or occupied by the per-
son may accompany an arrest.
FMCDH