I think it would be interesting to have a technology that lets cars communicate to each other, a variant on blue tooth technology that lets gadgets communicate.
If we could do this, we could synchronize car speeds, letting cars move like flocks of birds. This could save money by letting cars move into each other's slip stream and by letting cars move in unison and in coordination with traffic lights.
As it becomes more advanced, it would allow collision avoidance and perhaps even auto-pilot (or auto-driver) capability.
Blue tire technology. I think I'm going to go file the patent now. I'll figure out the technology later.