if you remove the black piece from inside the cabin (by the A pillar on the door)
you can get into the Mirror
assembly without taking it off. It would be very tricky, but you could somehow "stuff" the LED's in there, and it would glow.
it might render the Mirror
unable to move, so make sure it's where you like it.
You can feed the power wires down behind the door panel, and over to the firewall