2007 a6 3.2 Replaced front brake pads the other day and noticed I also needed tires. Drove the car to the tire shop after replacing pads and everything seemed fine. After my wife picked the car up from getting new tires all the way around and a alignment, we're getting a humming noise that is intermittant at any speed coming from the front end. At any time that it is present you can barely apply the brakes and it goes away. Removed both front wheels afterwards and double checked everything to be tight and clean.. Did some pad seeting afterwards and it seemed to help. Until today my wife called and said it was back. Any suggestions? Thank you in advance.

 

Could very well be the tires... My moms A4 howls like a wolf because she has cheap tires on it.