I think there is/was one with horizontal bar

 

Is that a cover or an entire mirror assembly? I only found covers while searching that site.

 

I've been meaning to do this, but is there a way to have them flash in sync w/ the turns and stay on all the time. Using relays you could get the sync w/ no parking lights or keep the parking function have the two blinkers alternate.

I believe it's a matter of law for safety reasons, including the colors used. Usually amber front and red rear, so u know what direction the car is headed.