According to the theory of relativity in physics, an object with mass cannot reach or exceed the speed of light. Therefore, it is not possible for a vehicle with mass to travel at the speed of light.
However, let's consider a hypothetical scenario where you are traveling at a speed very close to the speed of light. In that case, from your reference frame inside the vehicle, you would observe the light emitted by the headlights behaving in a normal way. The speed of light is always constant relative to the observer, regardless of the motion of the source.
However, from the perspective of an outside observer, things would appear differently due to the effects of time dilation and length contraction predicted by the theory of relativity. An outside observer would see the light from your headlights traveling away from you at the speed of light, but they would also perceive the distance between the individual light waves as shorter than what you would measure inside the vehicle. This phenomenon is known as relativistic aberration.
In summary, while you cannot actually travel at the speed of light, if you were hypothetically traveling close to that speed, the light from your headlights would still behave as expected from your perspective, but it would appear differently to an outside observer due to the relativistic effects.