I could be completely wrong cos it's a long time since I studied this but....
First of all I should mention that it's illegal to drive a car at the speed of light, even on the autobahns in Germany.
Secondly it's impossible to travel at the speed of light because your mass approaches infinity as you approach the speed of light so your own gravity makes you collapse in on yourself, or something like that.
However ponder this....
A man is travelling on a speeding train. He switches a torch on and shines it in front of him. As far as he is concerned the light leaves the torch at the speed of light. The train passes through a station and another man is standing on the platform. As far as the man on the platform is concerned is the light from the torch travelling at the speed of light plus the speed of the train? No, apparently time is going slower for the man of the platform so the light from the torch actually travels at the speed of light (and no more). Something to do with Relativity which I can't remember much about.
BRL, you might like to try this the next time you go to work.