I think I understand a little bit

Rating: 10/10 (19 February 2005)

I think that during conversation when someone is hopped up about something they tend to answer before they (the two persons speaking) are on the same page. Car making sounds as if it runs on gas. And also you are dealing with a 12 volt car system , 1.21 Gigawatts or not it is grounded so unless you are sticking two live wires in the gas tank or some outside source is causing a spark you could run watts and watts through it all day and nothing should happen but who knows.
As for the physics of the whole car time travel stuff. I think that perhaps the time circuits must cause some sort of warp in space-time like some sort of Spatial Flexure and the 88 mph is so that the mass of the car and person(s)in the car have enough inertia to punch through when the flexure forms.
Bottom line Car runs on gas Time circuits required the 1.21 Gigawatts (Plutonium) to open the Flexure.
How did they go to a certain point in time?? who knows my guess would be that they calculate certain frequencies to determine what point in time to arrive at. everything vibrates at a certain frequency. Nothing stands still.
Ultimately remember that it is just a movie