Forgive my ignorance here, lol.

If I am in my car traveling at or just above the speed of light and turn on my headlights, will they even make a difference? I mean, will the light coming out of them be traving at the speed of light+the vehicles speed?

Sorta along the same lines, driving my car at the speed of sound and honk the horn, what happens?

I know if I get hit with a basball thrown from a moving vehicle, it will have a stronger impact becase it is traveling at the base speed of the platform + whatever speed it gained from throwing. Same true for slight and sound?

Again, forgive the childish questions, but I assure you I have actually pondered this over the years, lol.

Thanks!
Jerry