What ever you do, don't ever turn ESP switch off on icy roads or snow unless you are the Stig!
Last year my mate drove out of the Aston martin garage with his new DB9 in the snowy conditions and thought to him self "wonder what this does" He never made the 1st corner and wrote it off. 5 miles on the clock and ended up in Hospital.
Never ever turn it off unless racing days:)
kind regards
Peter