I now know why Volkswagen Group is the world’s most profitable car company: it makes cars with cheap components that fail after 32,000 miles and then sells replacement parts at high prices for its dealers to install at extortionate rates. In the past six months, my five-year-old Eos Sport 2.0 TDi (bought from new and serviced exclusively by Alan Day Volkswagen) has required a new window motor, seat-belt latch and dual-mass flywheel at a total cost of £1649.23. The DMF particularly rankles – it is a known fault with this engine. Alan Day offered a derisory 10 per cent discount, which Volkswagen said it would only match. I have refused and now wish to go after them for selling a product with a known fault. Please advise how best to proceed.