This is for the wife's C300 AWD. Here's what's on there now: Conti Pro Contact, tread depth: front: 8/32" rear left: 4/32" rear right: 6/32" Since this car is used during winter, I'm inclined to get her some new tires before the first snow hits. From what I've read, snow traction really diminishes once the tread goes below 6/32". AWD and DSC help, but they don't perform miracles. I've decided on Conti DWS. The only question is, do I just get her 2 of them for now for the rear axle since the fronts still have plenty of tread left? Or is the winter traction of DWS so vastly superior that it would be too big of a mismatch and I should just buy 4 DWS and maybe try to sell the two CPCs that have good tread left? For the record, she drove on the CPC last winter and didn't have any issues, but obviously there was a lot more tread on them last year. Thanks!