As explained earlier, with the increasing use of ADAS systems on modern vehicles which have been added to increase driver/passenger safety, also provide the driver with information and warnings about what is happening immediately outside of their vehicle; it is important that these safety features (which in many cases is the reason people have chosen the vehicle) remain fully functional.
Many modern vehicles have semi-automatic gearboxes which are electronically controlled. As with a fully automatic gearbox, the towing vehicle needs to know it is towing in order to assist the driver in running the appropriate speed in the correct gear. When a trailer or caravan is plugged in, the gearbox system acts differently, to operate within the optimum torque range to accommodate the additional load.
Whilst many drivers have been towing for many years and have a great deal of experience, the modern vehicle is built in a very different way than they have previously. With many of the ADAS features being subtle, indeed so subtle many drivers are unaware of their effectiveness until a near collision.
Vehicle Specific Kits usually take a little longer to install and will often require some form of vehicle coding (this can be done by a reputable fitter) and are usually a little more expensive. They do, however, protect the towing vehicles systems, and enable the driver to be more aware of their surroundings.
As with some Universal Kits, the ability to have appliances operational within the trailer unit whilst travelling, and to protect the towing vehicles systems is a key benefit. They also come with the necessary fuses, relays etc to ensure they are correctly installed.