That thing is a pain in the *ss as it spins while trying to adjust(on mine anyways). I will get one and keep on hand as I am sure it will be going out as well. Definately looking forward to any ideas on where to get one. Sorry i havent researched yet.
go to a dealer they were only like 12 bucks. otherwise if you find his part # just do a google search and you can probably find somewhere that'll ship it to your house.