I'm a new S40 owner. I recently purchased a "slightly" used 2008 fwd S40, and when I accelerate swiftly at around 20 mph with the DSTC enabled it feels as though the front end shimmys? I had it to the dealer and they balanced the tires. I then disabled the DSTC for some time and it seemed to be better? Just wondering if anyone has had, or heard of anything like this before? Thanks!!