I have noticed a few times that my A4 swerves when I brake on the parkway (going between 45 and 60mph). This doesn't happen all too often but when it does it scares me because I cannot control it.
I have noticed it will start to swerve after the car starts to drift left.
Tonight was the worst, I was slowing due to traffic and the swerving almost made me hit a wall. It seemed like I lost control of the car. The tires also made that noise when you break suddenly and I wasn't suddenly breaking.
Is this something I should take up with the service center?

 

definitely a problem you should have looked into ASAP