One of my friends who lives in Holland and is very proud of how he spends the least amount of money on anything (he once drove a Trabant as the dealer in Rotterdam gave him a voucher for 6 months petrol) says he has been using some home-made cleaning clay on his 2006 333i for several years.
He reckons it is what sounds like pres-stick to which he adds a touch of flour and then vinegar. After washing the car and drying it, he sprays some water and very dilute detergent on the car before rubbing this stuff on, then rinses it off.
I must say the finish on his car is really superb. He cleans it with "clay" about twice in summer and once a month in winter, as the roads are treated with salt and grit in winter and this makes a terrible mess. I last saw his car in September and it was like new.
He reckons it is what sounds like pres-stick to which he adds a touch of flour and then vinegar. After washing the car and drying it, he sprays some water and very dilute detergent on the car before rubbing this stuff on, then rinses it off.
I must say the finish on his car is really superb. He cleans it with "clay" about twice in summer and once a month in winter, as the roads are treated with salt and grit in winter and this makes a terrible mess. I last saw his car in September and it was like new.