Highly concentrated, phosphate- and NTA-free, alkaline, high foaming precleaner for car and truck prewashing. The combination of high-quality complexing agents and special surfactants dissolves even stubburn incrustations such as insects, bird droppings, environmental and rim dirt extremely quickly and is therefore ideally suited in particular for heavily frequented carwashes and for non-contact high-pressure washing. Special corrosion inhibitors ensure high material compatibility with regard to sensitive components such as, eg, anodised aluminium. Also eminently suited for copolymer dewaxing. Optimally suited as well for biological service water treatment plants.