Speed of light

If my car was going at the speed of light, what colour would my headlights be?

an interesting thought expariment, even though impossible.  I think I will humor this for now. 
first thing's first, since this is impossible from the get-go, there are no wrong answers.
that said, I think that your headlights would create matter.  technichally, you would create a light beam with a wavlength of 0, or a frequency of infinity, so in essence, you would just create energy in a certain place in space.  doing this, you would raise the energy of that space until matter (frozen energy, by reletivity) spontainiously was created in that region.