Introduction

With the rear seat folded down, the space underneath appears almost useless. It's too shallow to store most gear and too cramped for anything practical.

Or is it?

As it turns out, this overlooked space is the perfect location for mounting electronics that need to stay secure while remaining completely hidden from view.

This build journal documents the design and evolution of Boogielander's rear seat power mount, from its humble beginnings as a piece of scrap wood to a purpose-built aluminum mounting platform that has survived years of daily driving, overlanding, and high-speed off-road abuse.

What is “rear seat power mount”?

In Boogielander, the space beneath the rear seat serves a purpose far beyond hidden storage. It houses the "brains" of the truck's auxiliary electrical system, including the Icom IC-2730A HAM radio, the Victron 12/24-15A DC-DC charger, and a Blue Sea fuse block with integrated ground bus.

These components are critical to the truck's electrical system, yet none of them need to be visible during everyday use. In fact, keeping them tucked beneath the rear seat protects them from accidental damage while preserving valuable cargo space and maintaining a factory appearance.

Like many projects, however, the current design wasn't the first attempt.

Version 1: Scrap Wood

Every good project starts with whatever happens to be lying around the garage.

Back in 2022, Version 1 was built from leftover scrap wood using a simple three-piece design. Two smaller blocks were stapled to a larger base plate, allowing the assembly to wedge tightly between the rear seat brackets using friction alone. The HAM radio, Victron DC-DC charger, Blue Sea fuse block, and circuit breaker were then attached using wood screws, creating a surprisingly sturdy mounting platform with almost no material cost.

And surprisingly... it worked.

For nearly three years and over 55,000 miles, the wooden mount survived daily driving, overlanding, and countless miles of rough roads without ever coming loose.

Eventually, though, time caught up with it.

After years of removing the mount for upgrades, relocating components, and general tinkering, the wood began to wear. The friction surfaces gradually rounded over, reducing the clamping force that kept the mount secure.

Version 1 had proven the concept.

It was time to build something better.

Version 2: 5052 Aluminum

The final push came after removing the wooden mount once again to replace a failed Chinese wiring harness. (That's a story for another build journal.)

With the mount already out of the truck, it became obvious that relying solely on friction was no longer the right solution.

There were really only two choices:

Build another wooden mount and repeat the cycle a few years later, or design something that would become a permanent solution.

The decision was easy. Instead of rebuilding with wood, the new mount would be laser-cut from 5052 aluminum and mechanically secured to the truck using the factory seat bracket bolts. The result would be a stronger mounting platform, more usable mounting space, and a design that would never rely on friction alone again.

Why?

Because #nomickeymouseshit.

The Design

Designing the aluminum mount wasn't simply a matter of tracing the wooden version and cutting it from metal. Aluminum opened the door to a much more refined solution, but it also introduced new design constraints.

The Sides

The factory rear seat brackets turned out to be the perfect foundation.

Each bracket has a small protruding section that could be used as a mechanical stop, preventing the panel from shifting forward or backward during hard acceleration, heavy braking, or rough off-road driving. Instead of relying solely on fasteners to resist those forces, the truck itself would carry the load through geometry. That meant the side profile had to match the seat brackets almost perfectly. Notches with generous corner radii were added to wrap around the factory brackets, while two mounting holes were precisely positioned to reuse the factory seat bracket bolts.

Getting those dimensions right wasn't as easy as measuring once and calling it finished. Each revision was 3D printed, test fitted in the truck, adjusted, and printed again.

Ten prototypes later... The geometry was finally right.

Mounting Slots

The wooden mount was essentially a blank canvas. Components were secured using self-tapping screws wherever they happened to fit. The downside became obvious almost immediately: every new hole was permanent. Moving a component meant drilling another hole, and after enough changes, the mount slowly became a collection of abandoned screw holes.

The aluminum version deserved something better. A slotted grid system provided virtually unlimited adjustment while allowing components to be removed, repositioned, or replaced without permanently altering the mount. As long as the mounting hardware lined up with the slots, almost anything could be installed. The slots were designed around M6 hardware, although M5 bolts can also be used with larger washers.

Early prototypes used square corners, but those quickly proved to be less user friendly during installation. Rounded slot corners not only make hardware easier to position, but they also reduce stress concentrations while removing unnecessary material. Sometimes the better design is also the lighter one.

The Result

The new aluminum mount addresses every limitation discovered during nearly three years of using the original wooden design.

The biggest improvement is secure mounting. Instead of relying on friction alone, the panel is now mechanically secured using the factory seat bracket bolts while the notched sides transfer acceleration and braking loads directly into the seat brackets. The mount simply has nowhere to go.

The second improvement is flexibility. Unlike the wooden mount, which required self-tapping screws and permanently committed every mounting hole, the slotted grid system allows components to be repositioned or replaced without modifying the panel. Future upgrades no longer require rebuilding the entire mount.

The aluminum construction also introduced some unexpected benefits.

One of them is heat management. The Victron DC-DC charger naturally generates heat during operation. While the charger is designed to handle it, mounting it to a slotted aluminum panel improves heat dissipation in two ways: aluminum conducts heat far more effectively than wood, and the open grid allows air to circulate around the charger instead of trapping heat against a solid surface.

The other unexpected improvement is cable management. The slotted grid provides convenient anchor points for securing wiring throughout the system. Instead of allowing service loops and excess wiring to move freely over rough terrain, the wires can now be tied directly to the mount. That seemingly small change reduces stress on electrical connectors by transferring vibration loads into the panel instead of the wiring itself. Coincidentally, that's also the most likely reason the previous Chinese wiring harness failed.

Finally, despite being significantly thinner than the original wooden mount, the 5052 aluminum panel is more than strong enough to support the combined weight of the HAM radio, DC-DC charger, fuse block, wiring, and future accessories, even during high-speed off-road driving where dynamic loads are considerably higher than the components' static weight.

Final Thoughts

The aluminum rear seat power mount is a significant improvement over the original wooden design. It provides virtually unlimited adjustability for mounted accessories while replacing a friction-based mounting method with one that relies on geometry and factory hardware. It also improves heat dissipation, simplifies cable management, and has more than enough strength to handle the dynamic loads encountered during high-speed off-road driving.

Best of all, once the rear seat is folded down, everything disappears from view. The truck retains a clean, factory appearance while keeping its electrical system protected and easily accessible when needed.

What started as a piece of scrap wood eventually evolved into a permanent solution that should last the life of the truck.

Good engineering doesn't ask friction to do a job that geometry and fasteners can do better.