We're big fans of LED lighting. It responds quickly, it generates almost no heat, it lasts for a long time and it uses minimal power. What's not to love?
You'd think the ND Miata would use LEDs everywhere. Oddly, it doesn't. It has LED headlights, brake lights and DRLs. The rest of the bulbs are incandescent.
We use LED replacement bulbs from Diode Dynamics because they're the best ones we've found. They're made in the US to high standards, not just the minimum price. They've got constant-current circuitry to protect the bulbs from transients and offer a three year warranty. Even their lumen ratings are based on actual measurements instead of advertising promises. You can buy cheaper LEDs, but you can't buy better ones.
For the side and corner lights, we have complete replacement housings that are either white or smoked when off but still light up the right color. Note that the complete housing sets and the rear turn indicator units are not made by Diode Dynamics. Some of those replacement housings have a slightly dodgy connector on them and are being sold at a discount while supplies last. We have a video showing how to install those.
If a certain location is not listed in the bundle, that means we do not currently have a solution for that specific bulb. Check back soon, we're working on more!
Note that we have not tested these on the Fiat 124 Spider. Please confirm the bulbs will fit your car before ordering.
About hyperflash: the flasher in your Miata expects some resistance from the light bulbs. If that resistance isn't there, it will flash faster, like you have a blown bulb. That's a clear sign of someone who has replaced their LEDs but hasn't paid any attention to actual function. It's a little embarassing to see. The solution is to add inline resistors - they're included with the rear turn indicators. You will have to purchase them separately for the fronts.