Isn't this more an issue of how one chooses to wash your car? I have a reasonable sized one, an Audi Avant and can wash the bodywork satisfactorily with just two buckets of water, one clean and one containing shampoo. Rinsing off would be just about possible with maybe an additional bucket of clean water.
Whilst I don't live on the coast we do get some seagulls so a fair amount of cr@p to clear...
Cleaning the alloys I use the incredibly cheap Elbow Grease cleaner available from B&M - this contains the same chemicals as the overpriced specialist ones that Halfords and similar sell, however this can be bought in 1L spray bottles @£1.99
Whilst I don't live on the coast we do get some seagulls so a fair amount of cr@p to clear...
Cleaning the alloys I use the incredibly cheap Elbow Grease cleaner available from B&M - this contains the same chemicals as the overpriced specialist ones that Halfords and similar sell, however this can be bought in 1L spray bottles @£1.99