Don't be tempted by cheap hand car washes
Quick answer: A £5 hand wash is a false economy on a lease car. Dirty buckets, gritty cloths and harsh chemicals cause scratches, wash marks and chemical burns that an end-of-lease assessor can bill you for. Use a well-maintained automated wash or a self-service jet wash, or a hand car wash you would trust with a new Aston-Martin.
Every time you clean your car you mark the paintwork -- that is just a fact. Even the insanely expensive detailing services in Chelsea that look after celebrity Ferraris and Lamborghinis cause wash marks, which is why they machine-polish the cars afterwards.
Generally speaking, wash marks are not something you need to worry about on a lease car. An automated wash will give you worse marring than a careful hand wash, but nowhere near the point where you would be charged for excessive wear and tear.
A sign that says "Hand Car Wash £5" is a different matter. Most of the time the lads do a decent job, but not always -- and we have seen some terrible things.
We have watched them in supermarket car parks wash a dozen cars in a row without changing the bucket, slap a sponge full of grit onto the dirty side of a car and smear it around, drop cloths and leathers on the floor and carry on using them, and routinely use a harsh TFR meant for brake dust to clean the entire car.
Barely a week goes by without us seeing a car with chemical burns on chrome, plastic and rubber, smothered in swirl marks and micro-marring, and sometimes scratches on the glass as well.
From our side of the fence we can usually put that right with paintwork correction, and often do something about the burns too -- we do not know until we try, but we can normally at least improve it.
An end-of-lease assessor does not have that luxury. They are looking at photographs, not the car, and the safe call for them is to price up a full respray and a new set of exterior trim. That is a costly bill to land at the end of a lease. For what the cleanliness standard actually requires, see how clean does a lease car need to be.
Clean the exterior about once a month. A well-maintained automated wash or a self-service jet wash is fine. There are genuinely good hand car washes around, but ask yourself honestly -- if this was a new Aston-Martin, would you trust them with it? If not, do not trust them with your lease car. The question of whether dirt alone triggers an explicit lease charge is separate -- see will I be charged for a dirty car for where that threshold sits.