How to clean a car that's covered in dust

Honest John advises on the best way to remove a thick layer of dust from a car

Car wash
Avoid drive-through car washes if you're car is covered in dust

My new BMW 435i is covered in a heavy layer of dust due to the demolition of a building next door. What would your advice be about the best way of removing it without damaging the paintwork? It is so bad that I have asked the insurance company to send a claims assessor.

CB, via email

No rubbing, no sponges, no drive-through car wash. I'd advise using lost of plain hosepipe water to lift the dirt into suspension, then probably a Karcher or jetwash at a low setting. Then again, if the UK gets any more heavy thunderstorms, you might find this cleans your car up before the insurance assessor gets there.

Email your queries to honestadvice@telegraph.co.uk (please include your full name, postal address and phone number). More Honest John articles.