Are warranties affected by towbars?
With new vehicles some dealerships might tell you that the towbar should be fitted by them due to the warranty. This is in fact a lie, under EC competition law, car manufacturers and/or dealerships are not legally allowed to prevent or hinder after market suppliers from working on newer vehicles.
This law is called is called Block Exemption and is in place to prevent manufacturers and dealerships monopolizing the market and to help promote free competition. More often then not dealers will higher independent towbar fitters to fit the the towbar when selling to you the vehicle with a towbar, due to the cost of employing a professional fitter vs the cost of just hiring one.
Read more on block exemption here: https://ec.europa.eu/competition/sectors/motor_vehicles/legislation/legislation.html
When getting a towbar and electrics fitted by an independent company, the parts used must be of the same quality as if it was fitted by the manufacturers or dealership. If the parts are of a cheaper quality warranty providers will not fix them free of charge, should any issues occur.
For vehicles registered after 1998, all towbars must pass a certain quality control and strength test before being approved by EC 94/20 type regulations.
When designing vehicles, manufacturers must provide mounting points for a towbar to be bolted to. Due to this, both manufacturers and after market towbar manufacturers both design their towbars from the same point.