(a) A garage insurance policy may provide that a garage customer is not an insured under the policy and that the coverage under the policy does not apply to a garage customer except to the extent that any other insurance coverage that is collectible and available to the garage customer is not equal to the minimum financial responsibility limits specified by Chapter 601, Transportation Code.
(b) Notwithstanding any provision to the contrary in another insurance policy as to whether the insurance coverage described by Subsection (a) that is provided under that policy is primary, excess, or contingent insurance, or otherwise, the other insurance coverage is the primary insurance as to the garage customer.
(c) A garage insurance policy containing a provision described by Subsection (a) may not cover a garage customer except to the extent permitted by this section, notwithstanding the terms of the other insurance policy providing coverage described by Subsection (a).