The ball weight on your car should be between 9% and 11 % of the total weight of the van when loaded, the factory reading means little. It is your responsibility to balance your van and car so it will tow correctly. In our case our topender weighs in at 3500kg loaded which meant we have around 350kg on the ball. We had to upgrade our car with a lovells GVM and Tow pack to be compliant. Our 200series is now plated with a GCM(gross combined mass) of 7800kg that is a GVM of 3800kg for the car and a tow capacity of 4000kg. The ball height is also important the car and van should be level when loaded ready to go. When you have it right you will feel it, the car drives well and the van does not wander over the road. Use a weigh bridge to weigh the car when connected to the van, then car and van when connected, then van when connected. Disconnect the car and weigh it seperatley you will now have all the info you need to get it right. It is worth taking the time to do this as you can then travel with confidence knowing you have it right.