Hello forten, at Aldi-Nord there was a car wash concentrate on Monday. A means for: Car wash outside (incl. gloss effect) Interior wash Insect remover Rim cleaner On 8-10L water you give according to instructions 150ml concentrate for outdoor wash / rims / insects. For internal cleaning almost half (approx. 60ml) of concentrate. I filled on my 1 L pump spray bottle 20ml concentrate, well shaken and sprayed on rims and insect-infected area. Result: but very too On the rims the dirt ran down just fine. The insects also solved it well. Cost per litre: 2,99 EUR (I stored 2 liters as a precaution). Cheaper can not clean a car. In my opinion. Greetings Andy