sorry its a bit late but if you can get hold of Swarfega Powerwash Ultra Concentrate it is the same colour and and works much better than muc off .these are taken from the actual write up.
FEATURES & BENEFITS

Concentrated Formula - To maximise the chemical concentration for diluting with water
Effective - Dilute to form an effective cleaning solution.
Economical - 2.5 litres of concentrate dilutes with water to make 25 litres of ready to use Traffic Film Remover.
Storage - Reduces storage requirement and optimises free space.
Biodegradable - will degrade in *sewage systems. *Local conditions may vary, for further advice contact Deb or the Environment Agency
Compatible - With all hot and cold vehicle cleaning equipment.
Silicate free - Prevents etching of glass or damage to original paint finishes when used correctly.
Prevents scaling - Reducing maintenance costs and prolonging equipment

it only costs �13 + vat
and thats for 25 litres