Notwithstanding any other provision of law, except for any willful or grossly negligent act, a fire company or rescue company, and the personnel of a fire company or rescue company, are immune from civil liability for any act or omission in the course of performing their duties. The immunity granted by this section is waived with respect to actions to recover damages for the negligent operation of a motor vehicle to the following extent: For a self-insured fire company or rescue company, liability shall extend up to the minimum insurance limits imposed by § 17-103 of the Transportation Article; and For a fire company or rescue company insured by an insurer authorized to issue insurance policies in this State, liability shall extend up to the maximum limit of any basic vehicle liability insurance policy it has in effect, exclusive of excess liability coverage. The immunity granted by this section is not waived and may be raised as a defense as to any amount of damages claimed above the limits in this subsection and as to any other action for damages not involving the negligent operation of a motor vehicle.