You would never reach the speed of light as time relative to you slows down as you approach it. Also, turning on the headlights, and measuring the speed of the light coming off them will always equal 186000 miles a second... not + whatever speed you're going.
Wouldn't they still shine? You just wouldn't be able to see them from the front.
Not a physicist, I just dabble. Its a fun subject... From what I understand...
As I said, The closer you get to the speed of light, time slows down. You will never
reach the speed of light, Period. Therefore, yes, your headlights will always shine out in front of you, its just that the speed coming from the lights themselves doesn't change just because what its coming from changes speed.