just another thought. if you live in the country like me where mainstream city technolgy is slow to arrive the generator is a good idea. also cost less than a tow truck, is portable and no wait time. nice gap measure until all or most tow's are equipt with portable chargers. just a thought.
Of course I can't find the link, but I think it was on this Ford Focus Electric forum where somebody had talked about a turbine powered tow behind generator. Any generator that you stored in the trunk would have to be so tiny (so it's light enough to pull out and use when necessary) that it would take forever to charge. Any generator big enough to do a decent job will be heavy, large so you'd need to pull it on a trailer.