You pay no registration fee and no excise tax on one vehicle if you lost, or lost the use of, one or both arms at or above the wrist or one or both legs at or above the ankle from a service-connected cause.
Apply at a New Mexico Motor Vehicle Division office when you register the vehicle, with your discharge paperwork and VA documentation of the loss or loss of use.
Your DD214 showing an honorable discharge, proof of New Mexico residency, and VA documentation showing the service-connected loss or loss of use of an arm or leg.