General rule of thumb: If Subaru doesn't offer an OEM camera as a dealer-installable option (post delivery) for your particular car model, then your car is not pre-wired for a camera. In Foresters that are pre-wired, the harness is already plugged into the back of the HU, so the only work you or the dealer needs to do will be at the tailgate.
So if you're keeping a factory head unit, and if your car is not pre-wired for the OEM camera, you'll definitely want my 8-pin or 16-pin rear camera harness (depending on OEM HU model). That's the easiest way to connect the camera into the HU.
The remaining thing you'll need to decide is whether to include the 6 Volt power lead on my harness. For an OEM camera, you'll definitely want that. It turns out that many aftermarket cameras will work from 6V (some even as low as 3.5V).
For Subaru HUs besides the Fujitsu Ten nav, you can usually power an aftermarket camera from the reverse lights (unless their instructions say otherwise.
One example).
The OEM Fujitsu Ten nav HUs must see a video signal from the camera during boot up (or the HU will decide no camera is present, and leave the feature disabled). So for this HU, you
must power the camera from the HU's 6V supply, or from +12V Accessory (on whenever your key is on). For a camera that needs more than 6V, you can use the HU's power lead to run a small 6V relay, which in turn switches the camera's 12V supply on/off.
Arguments against choosing an OEM camera for a car that is not pre-wired for it:
- The OEM cameras are very expensive. The Crosstrek's camera is obscenely expensive (more than $200 !).
- They require 6V power (so unless you want to build a 12-to-6 V converter circuit, you'll need to get that power from the OEM HU)
- They have a short harness with a proprietary plug. You'll need to either:
- Cut off that plug and solder on your own plug, or
- Buy the OEM tailgate/trunk harness that includes the camera socket (~$40), cut of the segment with that socket, and solder on your own cable.
In both cases, you'll need to add a longer cable to reach from the trunk to the HU.
- Since the car isn't pre-wired for the OEM camera, you'll need to drill or saw a hole to mount the camera. So the job is no easier than what you'd have to do for an aftermarket camera (and there are some that look the same as OEM -- check out the Rydeen DUO and MINy cameras).