My tow bar (13-pins) cost me 1250€, and they kind of butchered my the lower rear bumper by opening an unnecessarily big hole into it.
Well at least they shouldn't bust my balls if I ever have an issue with it as it was paid and installed as an option not aftermarket.
Reading the title, I thought you were talking about towing bars and that is something you also need to consider if you get a tow hitch installed. The tapered hole to screws towing eye behind the little removable hatch that you would use with a towing bar or strap/rope, well, it is blocked by the tow bar, so if you ever want to tow a car with you MG4 with a hitch, you will need to use the hitch itself.
And the hole is just blocked not even used by the harness itself, kind of laughable.
The 500kg max feels like legal limit. Here in France, 500kg or less trailers don't need registration.