A couple years ago I bought high & low beam WHITE bulbs for my 2005 Silverado from http://www.eurodezigns.com
They advertised a lifetime warranty for a mere $6.95 return fee.
GUESS WHAT - I had a bulb go out so I took it out put it in an envelope with a $6.95 MO and mailed it back as the instructions say on their web site. Within 5 days I had a SET (2 bulbs) in the mail. So now I have a spare if another one goes out.