There are two reasons the gears go south.
1. Hot plastic worm gear melts the plastic. Might get to be more than 300F in Texas.
2. The tracks that the moonroof rides on get dry and cause excessive torque to be put on the motor/gear.
Every so often, I put some more machine oil in the tracks on mine. The motor seems to run much smoother after I do.
My idea a while back was to make some metal gears. If that guy can make a mold, and inject it with wax, I know they can be made in Bronze (which is fairly cheap). It would be done with the lost wax method, just like jewelry. I just had a hard time with the mold.
