I don't think they go in to Warn directly for warranty service, they go to an authorized repair center. Shipping costs each way would add up. Six States is our local shop. Looking at Warn's site you've only got a couple choices in Cali.
I will say that in my experience Warn has got to have some of the best customer service in this and likely many other business lines... They treated me very well indeed. They not only made me whole with a problem, but did it with admirable flexibility and willingness to help.