I recently bought a 2016 Mazda 2 with 20k from a dealer and noticed what can only be described as a loud noise like a wind tunnel. Sitting in the drivers seat it appears to come from the rear, possibly n/s. The noise increases with road speed and noticed at around 40mph and particularly constant at 60mph. It isn't the same as tyre or road noise.

The dealer told me to take it to Mazda for a second opinion and the tech said he had never heard a noise like it in 20 years at Mazda and first thought -wheel bearing; then said it sounded like wind noise through a missing grommet after checking what the selling dealer had said. When I got the car back 'fixed' they said it was a grommet in the rear light, but soon as I drove it the noise was still there.

The car has the typical 3 month warranty, and of course wind noise isn't something to reject a car after 3 attempts to sort it out, that is of course if it is wind noise.

Mazda said it didn't look like there had been accident damage or paintwork. I drove their courtesy car and no similar noise. They said my car sounded like driving with the rear window open and they tried taping panels and gaps, but the fact they said it was fixed when obviously not, means a lack of confidence in taking it back again.

Any suggestions to where I stand. The noise isn't normal or like any wind noise I have heard even in old cars. Wheels don't seem to have any play, so a mystery so far!