I can’t help with the car itself but when I fitted a towbar and electrics to my 2013 Honda CRV I just wired it via a bypass relay.
The CRV seems to have a computer for everything and I tried to test things to see what wire did what lamp (indicator,brakes etc) before I decided on a bypass relay, it just went berserk at me and needed a battery reset! It was the best option for me being a DIY’er and is easy to fit, takes the CAN system out of the equation and works very well