Hi all,

I have a 2016 U.S.-spec L405 that came with the standard fixed rear bench and the basic front seats. To be honest, I find the front seats too firm and uncomfortable on longer drives, which has me looking to upgrade the fronts to the 22-way spec.

While digging into what’s involved with the fronts, I started wondering whether it’s also feasible to retrofit the rear power-reclining seats (keeping the 5-seat layout, not going all the way to Executive Class with the full console).

A few things I’m hoping members can clarify:

Fronts: For those who have swapped to 22-ways, what’s plug-and-play vs. what needed coding? Did you reuse your original DSM or code the car to accept the donor modules? Any pitfalls to watch out for?

Rears: Do non-equipped cars have the “super slouch” / recline harness pre-run, or does this require a full donor loom? Are the recline switches only in the rear door cards, or do the seats have dedicated modules?

Coding: Has anyone successfully coded an L405 to recognize both 22-way fronts and power-recline rears?

Other parts: Do I need a different parcel shelf for the recline travel, or can the standard one be reused?

I’ve found threads about troubleshooting factory-fitted power rear seats and a lot about Executive rears, but not a clear retrofit write-up for either 22-way fronts or power-recline rears on a non-equipped 2016.

If anyone has done either retrofit (or both!), I’d really appreciate details on wiring, coding, and parts needed. I’m trying to improve overall comfort front and rear in one go.

Thanks in advance!