hmmm.....welll.....first off, you don't got 4 seats.....you got two and a bench, no?
and the neons come in round tubes......you can get them anywhere between 6" and 48" and in I think, blue, purple, and green......unfortunately, they stopped making pink
they'll all come with plugs to plug into your lighter socket....all you'll have to do is splice your wires and then hook them up to a switch of sorts......best way would be to ground all the lights, and then have a power source (i.e. hard line to lighter socket) connect to your switch, and just use the switch as a breaker for the power....
so, have fun, and keep it tasteful, eh?
else someone may shoot you....:p