I have a 2004 model VZ Commadore with a 2100kg Holden tow kit which replaces the rear struts with a gas tpe that can be pumped up to raise the rear of the car as well as a higher rated tow ball capacity.
I get very good fuel enconmy when towing my car around 13ltrs/100klm and can tow at speeds of 120+klm/h if needed but usually sit at the speed limit.
Going to the track i take my full tool kit, jack, spare oils, ratchet gear, spare parts, stands and luggage in the boot (sometimes some of the luggage is on the back seat).
Trailer is over 500kg (says 500kg on the plate but i know it is over it) and car around 1200kg.
Only issue i have is with the trailer being too low (put 100ml drop axles on it) and it can scrape going up driveways and the likes. This might be a good option perhaps?
Key is the tow kit and electirc brakes,
Matt