When driving along the motorway in snow/icy conditions the cars rear end slips quite violently to the left on straight roads (always to the left) and it feels like the car is just about to fishtail. This appears to happen randomly both when accelerating and when not. No warning lights show up on the dash. I tried to describe this problem to my local LR dealer and he said I needed to replace my winter tyres which still had 5mm of tread (4mm is the law here in Austria). Although I didnt believe this to be the problem, as the car behaves magnificently at speeds lower than 60 km/h in very slippy conditions, I replaced the tyres last week and I am still having the same problem. I am experienced in driving in the snow and have never had this problem with any car previously. I am neither trying to turn, brake nor accelerate heavily when this occurs and feel that I can only drive around 60km/h on the motorway when other cars/vans/lorries are clearly comfortable driving faster. The car is a RRsport supercharged 2007.

Any thoughts on what the problem could be?

Need to get the geometry checked on the car - have had this on a Merc SL, which had air suspension and felt like same feeling as if shocks had gone (which of course it didn;t have) but it turned out the alignment was very much out.....just an idea...I'm not an expert....