Many years ago my Dad and I used to apply Waxoyl to his car once or twice a year. He always used to run British cars and I remember several Morris and Austins culminating in his Austin 3 Litre and then a lovely Rover SD1 V8S and so on, Dad was very faithful to UK-built cars and he later had a TVR too! In those days cars were made from very mild steel and the UK councils would always use salt to melt the snow and ice (they still do, as far as I know) and so rust was always a major threat, thus Waxoyl plus other products.
Dad used to purchase big cans of this stuff and it was thick, black and horrible. We used to warm it on the stove in the kitchen and then head outside with the hot can and 2 paintbrushes to spread as much as possible onto the underside of the car and of course loads of it fell on us!!! It took several showers and Fairy Liquid to remove the horrible stuff from skin. In those days the exhaust pipes were also very cheap and thin and needed to be bandaged up or replaced every year!
Fast forward to today. I just purchased six spray cans of Waxoyl and wow what a difference! This product is clear (not black) and applies a layer of clear sticky stuff to the parts you wanna protect and thus without covering the person in charge of the can! I have started to apply the clear stuff to my Vito van and I intend to apply some to my old S4 plus the Tiguan and my bikes too. FANTASTIC product.