relay? I know for some cars a relay is not needed for but for most it is. I'm sure someone by now has installed some LED turn singles in an xD. I just don't want to install some LED bulbs then have to deal with that annoying rapid flash.

 

http://superbrightleds.com/tail-brake-turn.html

 

You need a resistor, not a relay.

 

You can use a Heavy Duty Flasher (An electronic - solid state might work too)

The heavy duty flasher will flash at the same rate irrespective of the load current that the lamps draw. The Solid State ones are nice and quiet :>)