Every week a Guardian Money reader submits a question, and it’s up to you to help him or her out – a selection of the best answers will appear in next Saturday’s paper.

This week’s question:

We need to sell our family car but, as we’re short of the time to do it privately, we’re considering using one of the companies that promise a hassle-free purchase. Has anyone used WeBuyAnyCar or thecarbuyinggroup, and what was the outcome?

Do you have a problem readers could solve? Email your suggestions to money@theguardian.com or write to us at Money, The Guardian, Kings Place, 90 York Way, London N1 9GU