Hi, only had an S3 a month or two so I'm trying to learn as much as I can. I've felt the rear wheels grip when pulling away when I had a little wheel spin from the front so I think it is working ok. However I have just tried to reverse off my drive which is uphill and at the minute got a fair bit of snow on it. Got half way up then the front wheels started spinning and stayed spinning for a couple of seconds and I felt nothing from the back wheels. Does the haldex switch off in reverse gear??