05 Passat Estate – considering fitting a towbar and I keep seeing references to bypass relays.

Why do I need one?

Oh and are detachable bars / swan necks easier to fit as you don’t have to cut the bumper?

Ta

To avoid overloading the wiring, to decipher the CANBUS wiring signals (one wire controls different lights depending on the voltage sent) to prevent false bulb failure waarnings, to provide the legally required audible beep (or visual indicator) that the trailer indicators are operating correctly.

(as you keep seeing references to the relay, I’m taking that to mean your car does have CANBUS wiring to the rear lights…most if not all modern cars do)

Don’t know about fitting, but I’d get a proper flange towbar if you are mounting a bike rack to it…the racks that clamp to the ball tend to gouge the ball making it useless for towing.

You will still need to cut the bumper but is usually underneath and out site. Westfalia detachable are very good and supply VW with their OEM towbars.

Witter do detachable flange balls now. I just had a fixed flange ball fitted (08 volvo v50) without needing a bumper cut, it just depends on the car / towbar combo.