[instalher]

there is a very annoying thumping sound centred around 65hz very very annoying, same as on my 323i when i hold down the diffuser.. but all the time on the x1. the diffuser is just a mesh screen which is slowing down the wind but there still is a tremendous vortex created by wind speed, i dont have a wind tunnel but, that is what causes the noise. its the speed of air flowing over the hood and going in the car through the hole. thus a diffuser to slow the speed down or aggitate it enough to not enter the hole.. the screen on the x1 is not doing its job properly. i must talk to r&d on this one..lol... say for this problem.. very nice ride..