Under for what it's worth:
I have a working trunk/cargo light fixture, but often I have the trunk open at a show. I hate taking the bulb in and out, but figured that it would run the battery down if I just left it on.
I recently replaced the trunk bulb in the 2013 RT with an LED bulb for the same reason. And I found this bulb on EBAY for ~$8 (
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&vxp=mtr&item=271477201965). It's a bit larger than the standard bulb, but it fits perfectly in the space. And it draws significantly less current and generates a lot less heat.
Of course, it won't work for the purest, (if you are a purest, I have an extra bulb for you). But I like having the light, and it's a good compromise.