The day my VW quit on me a little down the road at 0 dark 30 and I had to walk back to get the 240D, Meritline sent me an email sale message on these:
http://www.meritline.com/solar-flashlight-with-car-char---p-25424.aspx
I am normally immune to this sort of stuff, but , in a weak moment, I bought two of them (they were about $8 shipped). I have had them for about a month.
I am amazed at how bright and long-lasting the light is on these. I haven't had to use one in an emergency, but I think you could probably handle many minor roadside repairs with one of these. The light is pretty concentrated and useful for close to an hour. Of course, time will tell how long they will operate until the built-in battery gets lazy, but, so far seems like a nifty item to leave in the car. I keep it in the tray between the seats on the 240D and it seems to charge just fine there.
Rick