Daytime Running Lights + Switchback LED’s

MX52Z

I don't think it has to be that complicated. Depending on the choice of bulb, LEDs aren't going to draw enough current to require a relay.

No, the wiring is up to you. The 7443 bulb is dual filament meaning it's actually two bulbs in one. It has three contacts: common ground, power for one filament and power for the second filament.

The Z uses a 7440 single filament bulb, obviously just for the turn signal. (Other cars use a 7443 dual-filament bulb to as both turn sigal and parking/running light). So if you swap the Z's 7440 with a 7443 bulb, you're basically adding another set of bulbs within the bulbs that you can wire as you see fit, either to come on with the ignition or wired to a switch in the cabin.

So the premis here is to have a bulb that acts as a regular amber turn signal but also add white DRL function and that's why "switchback" bulbs are mentioned here, because they are one color for one function (white for DRL) but then switch back to another color for a different function (amber turn). Some switchback bulbs feature a very powerful forward element such as a white, 5W Cree for DRL while using smaller and less powerful LED arrays of amber for turn signaling.

As someone also mentioned, it would be nice to have amber DRLs like Vettes have so in that case, you'll just look for a dual mode 7443 amber bulb that flashes amber when turning but also glows amber for DRL.

By the way, this also applies to cars with 1156 (single filament) bulbs that one can customize with 1157 (dual filament) bulbs and harnesses.

I've done this on other cars and was preparing to do my Z until the OP created this great thread. In order to use 7443 bulbs, the wiring harness has to support that third wire. Usually, you can just get the harness for $2 each but according to the OP, the Z already has that third wire.

Since I haven't done this yet, I'm hoping the OP gets back soon with some picts because I'd like to see what he did with the stock wiring before I go taking mine apart.