I left mine still in working order because it is hidden by the spoiler anyways. Also note that if you should somehow accidently break your spoiler; then you could still drive your vehicle with an operating 3rd brake lamp until your new reordered spoiler was shipped to you.
Check ebay... Vendors such as spoilerdepot.com and autoearth.com both auction them off regularly for around $160 (painted)... or you can just pay a little more and buy direct off their sites if you don't like auctions.