Traffic Film Removers (TFRs) are extremely strong cleansers designed to blitz contaminants at a pre-wash stage, so that the wash stage is made easier (and safer) later on. They are also very good at stripping old wax layers or for attacking grime that shampoos can't touch.
Crudzilla is made from a blend of detergents, citrus solvents and caustic cleaners so there's no doubting its effectiveness. This is NOT a pH neutral product and can give existing waxes, sealants and delicate finishes a hard time. So make sure you rinse thoroughly with water after use, don't leave it on paint indefinitely and use with caution.
Available in a ready-to-spray 1 litre version, or as a great value 5 litre refill.