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 or for attacking grime that shampoos can't touch.
Crudzilla is made from a blend of detergents, solvents and caustic cleaners and the concentrated version even unblocked the Dodo Juice sink... so we know it's strong enough! Just make sure you rinse thoroughly with water after use. Something this, erm, effective, shouldn’t be left on paint indefinitely and can damage sensitive trim, so use with caution and always, always rinse. Did we mention that you have to rinse? Rinsing is good.
Available in a ready-to-spray 500ml version to use out of the bottle, or as a concentrate/refill version that dilutes at 1:10 (that's 5 litres for maths fans) for regular use, or at 1:20 or 1:40 for milder cleaning duties. And if you're as adventurous as we are, use the concentrate version neat for unblocking sinks.