I have an original GM third brake light to a 2006-2011 Cadillac DTS. This lamp is in the original GM box, I bought it from Lance Buick-GMC on 3-30-15 and was installed on DTS at same time. Paid about $235.00 for lamp.
GM part #25844853. All LED lamps work from end to end.
DTS was sold, I removed new lamp and replaced with old one, which still functioned, (but dim). Price is $100.00 shipped to you in continental USA. Thanks for looking.