The cheapest, easiest and most fun mod for any NA/MK1 MX-5/Miata. 
 
This mod enables you to flash your headlights at anyone and everyone with a simple pull back on the lights stalk. Your pop ups will raise, the full beams will flash and then they'll go down. Bring the joy of pop-ups to the world.
 
Believe it or not, flashing your full beams without this mod just shines the lights into your engine bay... 
 
10 minutes to install, no soldering required. Full instructions available. 
 
NA MX-5s ONLY (Unless you've somehow got pop-ups on an NB)