The job's actually pretty straightforward :
- Get a bunch of ESP8266, and set them up to work as relayers. You don't have to use TCP/IP necessarily, all you need to do is demonstrate an ability for individual units to talk to each other indirectly, through the mediation of other units.
- Design and build a power plant working off the heat gradient provided by cars (you probably wish to include a capacitor). Because of the excellent energy consumption and wake-up specs of the ESP8266 you don't really need to extract that much energy.
- Deploy these, by affixing them to other people's cars, without seeking permision. Get enough moving around so you can actually pass messages through this network. You don't have to demnonstrate any sort of significant bandwidth, 1kb/day transferred is ample for this exercise.
The reason we want this should be obvious, but if it isn't : it's a weapon, and in some contexts much more damaging than a nuclear warhead. That said, bear in mind that step 3 is probably illegal, if marginally so. In any case you will be dealing with an absolutely petrified and consequently quite irate USG apparatus, so don't expect much common sense.
Bitcoin available to defray at the very least the cost of materials.