I have a dc inverter plugged into my cigarette light. It's enough to power my 150W halogen work light that I rigged up firmly on the back seat armrest. I have a couple of sheets of that stuff plumbers use when soldering so as not to burn nearby wood. It looks horrible, but it's very bright.
This is a $20 diy...$60 if you don't want it to burn your leather!
Upcoming NYC dates: Jan 8 and 27. See Facebook for other shows and PM me if you can make one...love to see you there!
Mangofy your E46!