READERS helped me out with suggestions of what chemicals to use to rid myself of annoying marks left by brown sticky tape on my car paintwork, after I had attempted to fix a piece of cardboard on my windscreen to stop it freezing. I ended up using white spirit. It worked a treat.

Allen Jenkinson added WD40 to the list of alternatives. He adds it could also be worth spraying car locks with it in the winter. “WD40 stops road salt corroding the insides of the aluminium lock barrels,” he says.

So now you know.