TTH I've done physics so here is my reasoned answer in detail
Ok. Let me just get this straight in my head. I'm driving a car at the speed of light... 299,792,458 meters per second? I'm sorry, but the question is flawed in many parts, which I will go into:
1. I was to try that on earth, not only would I need the reflexes of a Jedi, but I would have to have some kind of car/boat hybrid. Sadly, the question is not "what if a boat-car was traveling the speed of light..." so we can't do it on our bluey, greeny mass of dirt. This takes us into point 2.
2. Have you ever tried to get a car into space? Jesus man, that's the looniest idea I have ever heard, and one of my friends suggested once that we go clay pigeon shooting blindfolded...(we didn't, but still a crazy idea.)
A car in space is just not doable, maybe if it was modified to serve as a space craft as well as a car. But that takes us back to point one.
(Anyone else see this turning into Asimov's three laws of pissing on the Theory of Relativity?) This, ties in neatly with point three.
3. Einstein, a crazy haired German once said that it is impossible to ever go faster than the speed of light. Was he right? Who knows, but that's not the topic under discussion here is it? Let's take him at his word and assume that the latter is true. So, nothing can go faster that the speed of light. Granted he doesn't say that an object can go AS fast, but he's dead now, so we can't question him on it...lucky git!
4. Speaking of being dead, have you ever been on a really fast rollercoaster? I'm sure you have. But, they don't make a roller coater that can do anywhere near as fast as the speeds we are talking about here. Traveling at the speed of light would, in theory, liquefied every major organ in your body, pulverise you into the seat, and Christ knows what else. Bottom line, it's not going to happen!
Anyway, as an answer is needed here, I'm willing to over look all the above points and wrap things up. Let's just say, that for some unknown reason there is a car is space. Also, this car has been fitted with some kind of star trek style doohickey that stops you from becoming goo when hitting insane velocities.
That all being said, the car hits the speed of light, (history in its self, mind) the driver turns on the headlights and what happens.....
NOTHING! Nothing at all, due to that fact that the light from the cars headlights has nothing to reflect onto, so the human eye cannot see it. If the driver goes out to have a look, well, he'd be dead of course and I'm not starting a load of new points just to explain that!
To wrap it all up. as I'm sure you have guessed, this was just a clever way for me to dart around the question as it's obvious that I have no bloody clue what I'm on about.