Regarding elephants and (shudder) washing the car. I have a 5l container of car shampoo under the sink. I use it for wasshing my bikes.
I have exactly the same car-washing regime, although my car shampoo lives in the shed.
I only have 1 litre, on account of no shed and limited space under the sink. I suppose I could store it in the car, if I had a car.