Would an observer behind you see your indicators winking if you were travelling the speed of light ?.
Depends on how fast and in what direction relative to you he's going. Doppler shift and all that. Slower than you and you get red shift. Faster and you get blue shift. Blue indicators. That would be confusing. The flash rate would also be different as time itself runs at a different rate depending on relative speed.
More importantly, if you were about to run into the back end of someone and you were going much faster than him, his brake lights would go blue so you wouldnt know you had to stop.
But while we are on the subject of hypotheticals, what happens if you are travelling at the speed of light and you turn your headlights on???
To you its normal. To an observer travelling at a different speed its not.
All these things are covered by the theory of general relativity.
Edit: Lots of interesting posts recently. I've covered everything from a horses arse to Einstein on Rotorheads.
