ISOFIX adapter plate

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Every modern car comes with proper child seat mounting points — so obviously the Mitsubishi L300 doesn’t.

After finishing the restoration, I wanted to start taking my son on trips. That’s when I realized the so-called “universal” Isofix adapters on the market are pretty flimsy and don’t allow for a truly safe installation of a child seat in this vehicle.

So I designed and built my own ISOFIX adapter dedicated specifically to the L300.

Main features:

  • Safe and solid mounting of an ISOFIX-compatible child seat

  • Use of the factory mounting points (no drilling or sketchy mods wherever possible)

  • Ability to install it on either the left or right seat of the second-row bench

The bracket was designed so that it can be installed on the right-hand seat of the second row without any drilling. For the left-hand side, only a single additional hole needs to be made.

It mounts directly to the factory seat belt mounting points on the seat frame, ensuring a firm and solid attachment.

The design was done in Fusion 360 using the sheet metal workspace. I prepared a proper workshop drawing with a flat pattern, so the part can be accurately manufactured on a CNC press brake.

Disclaimer: This adapter has not undergone any official testing, certification, homologation, or crash validation. It has no approvals or safety ratings of any kind. I’m using it entirely at my own risk and responsibility.