18. a. Nothing in this act shall be construed as imposing any liability on a dealer or distributor, or creating a cause of action by a manufacturer, or, in the case of an authorized emergency vehicle, a manufacturer, co-manufacturer, or post-manufacturing modifier, against a dealer or distributor, and nothing shall be construed as imposing any liability on a dealer or distributor, or creating a cause of action by a consumer against a dealer or distributor under section 4 of this act.
b. Nothing in this act, in the case of an authorized emergency vehicle and notwithstanding any other law to the contrary, shall be construed as creating, establishing or otherwise imposing joint and several liability for any action under P.L.1988, c.123 (C.56:12-29 et seq.), and a manufacturer, co-manufacturer, or post-manufacturing modifier shall only be liable for that percentage of negligence or fault in that action directly attributable to its respective degree of liability.