Unbelievably noisy tyres

Had two Goodyear Eagle F1 Assymetric tyres fitted to the rear of my Mondeo Mk4 and they now have 3-4mm of tread left. Over recent months they have become increasingly noisy between 10 and 30 mph to the point where I was convinced I had something seriously wrong with the car. After having everything checked...brakes, wheel bearings, suspension etc I proved it is the tyres by moving them to the front. I would never have imagined that tyres could make so much noise. They show no obvious signs of abnormal wear or faults.I took them to my friendly tyre supplier who knew instantly what the problem is and he showed me how the outer shoulders had developed step like wear around the circumference. He says it is common with this tyre and particularly when fitted to certain cars including Mondeo and Focus but many others too. He also advised that there was little chance of redress from Goodyear who will blame the vehicle and having contacted Goodyear it was clear that I would have to buy two new tyres (£300+) to be able to send these tyres back for inspection with no chance of a refund. I'll have to put up with unbelievably noisy tyres for as long as I can tolerate.... don't think it will be too long