My 2015 Jazz EX Auto (37,000) has had an intermittant problem for over a year now which started at 24,000 miles. When I leave the house I drive for 3/4 mile downhill to the main road (30mph zone). As it is an auto the brakes are used for most of this descent. Occasionally as I get to the bottom of the hill a loud metalic noise is evident which varies as the speed changes but does not disappear when the brakes are released. Once on the main road the noise disapears within 100yards. It appears to me as though something is heating up and expanding causing metal to metal contact which clears as soon as the brakes start to cool. In April'17 I took the car to my Honda dealer who reported no fault found. Brakes pads and disks were fine, car was serviced at 32,000 again pads etc were fine. Recently at 37,000 miles I reported the noise again to my Honda dealer who again found no fault but recommended a strip down and clean of the rear brakes AND new disks and pads at the front (70% worn pads). As the problem was evident 13,000 miles ago I am not confident that any of the recommended work would resolve the issue. Thoughts welcome!