October 2020 — on the gap between “there’s an adapter for that” and “there’s no adapter for that”

Most modern cars have a standard double-DIN head unit slot. You can buy an Android head unit for €150, an adapter plate for €20, and have navigation, Bluetooth, and a reversing camera in an afternoon. The aftermarket has been doing this since 2010.

The Boxster 986 is not most modern cars. The OEM head unit sits in a Porsche-specific housing with non-standard dimensions and a fascia that integrates into the centre console design. There is no standard adapter plate on the market. The options are: keep the original, buy an expensive Porsche-specific replacement, or solve the problem yourself.

I solved the problem.

The starting point

The 986 Boxster shipped with a range of head units depending on trim and year — from a basic radio to the PCM 1.0 navigation system. All of them sit in the same housing. The housing is wider than a standard double-DIN opening, with a specific fascia that holds the unit flush with the centre console.

The Android double-DIN unit is a standard 180mm wide, 100mm tall unit. The Porsche housing is wider and differently proportioned. A direct fit doesn’t exist. You either find a fabricated adapter (I looked; the market is thin and the quality variable) or you design one to the actual dimensions.

Designing the adapter in Fusion 360

The adapter plate has two jobs: fill the gap between the double-DIN unit and the Porsche housing, and mount the unit securely without rattles at motorway speed.

Measuring the housing correctly matters. The double-DIN unit has known dimensions. The Porsche housing is less standardised. I measured the opening directly, verified in three places (these things are moulded and not perfectly consistent), and modelled the plate in Fusion 360.

The design is a flat plate with:

• A 180×100mm cutout for the Android unit
• Mounting holes at the Android unit’s standard screw positions
• A profile that fits flush against the Porsche housing edges
• Enough material around the edges to distribute the load without flexing

The Fusion 360 model takes the geometry from the measurements and produces a clean, flat plate that can be verified on screen before any material is cut.

Machining it

I have a DIY CNC router in the workshop — a linear-rail machine with stepper motors and a spindle, controlled via a grey box with a standard GRBL controller. It’s not a Haas. It cuts aluminium slowly and with attention to feeds and speeds. It cuts aluminium sheet reliably.

The adapter plate is 2mm aluminium sheet. The CNC cuts the outer profile and the DIN opening, drills the mounting holes, and produces a finished plate in one setup. The surface finish from the toolpath is adequate — the plate disappears behind the head unit bezel and the Porsche fascia clips, so cosmetics at the edges are not the priority.

The result fits. That’s the result that matters.

The install

The OEM unit disconnects at the back — antenna, ISO wiring loom, and any Porsche-specific connectors (power antenna, telephone, etc. depending on spec). Some of these have to be adapted for the Android unit; a universal ISO harness adapter handles the audio and switched live. The power antenna trigger is a simple relay if the Android unit doesn’t support it natively.

The Android unit drops into the adapter plate, screws into the standard mounting positions, and slides into the Porsche housing. The fascia clips back into place.

Wiring notes specific to the 986:

• The Porsche uses a CAN bus for some functions; the Android unit is entirely independent of this
• The reverse camera trigger wire needs to connect to the reverse light circuit, easily accessible at the rear light cluster
• The steering wheel controls can be adapted with a separate module that reads the Porsche steering wheel resistor ladder and outputs standard CAN or IR signals that the Android unit can learn

What you get

Navigation that uses current maps, not a DVD from 2004. Bluetooth audio that actually works with modern phones. A reversing camera. Waze. Spotify. A touchscreen that does what you tell it.

What you lose: the integration with the original Porsche systems (outside lane departure alerts, speed warning chimes, etc. depending on original spec). For a 986-era car, these integrations were minimal — the original radio barely talked to the rest of the car. The loss is negligible.

The 986 is a driving car. The head unit is there when you’re parked or cruising; when you’re actually driving it, you’re not looking at the screen. The upgrade improves the parked and cruising experience substantially, costs a fraction of the Porsche-specific alternatives, and involves machining your own adapter plate — which is a better way to spend an October afternoon than paying someone else to do it.