On a 2016 boat, the chances are that it was installed prior to delivery, so contact the importer and ask them for the name and contact details of the firm employed to fit the autopilot.
I fitted my own autopilot system on my boat, and if I remember correctly the recommendations for the heading sensor were for it to be located somewhere near to the middle of the vessel away from the extremes of motion such as pitching or rolling, away from concentrations of metals, so the engine compartment was out, and I also considered placing it away from electrical or radio interference, away from anything that might have a magnetic influence upon it and away from anywhere where somebody might place something near enough to it by mistake which might upset the operation of the sensor. In a previous posting elsewhere on the forum, there was for example mention of someone's under wired supporting garment being placed too close to the sensor and causing deviation, so that should help to rule out some locations.
