Hello Marty. I had 200 lbs. of steel laying flat in the trunk of my '97 and '99 GTs (hey, I'm a steel salesman, it was an easy option for me) and this really helped keep the tail firmly planted in snow and ice.
Fortunately, I also had the superior traction of Bridgestone's famed Blizzak tires. I have yet to see or hear anyone have better results from a TRUE winter tire. And that's part of the dilemma; in my opinion, those of us that do drive our Mustangs in winter HAVE to give up a fair amount of 'performance' and go with a strictly winter-type tire. It ain't sexy, but man will it ever save your arse!
I live and drive in Toronto Canada, and for the most part, there are very few stretches of time with constant snow-covered streets. That's in part why we pay such huge taxes up here...to get our city streets and highways cleared quickly and often. So, the remainder of the time is usually just wet slop which freezes and turns to ICE PATCHES overnight! I need the security of icy traction more than snow.
Today's tire companies have come a very long way over the past couple of years, and most offer a great combination of ice and snow traction options (depending on your needs). GO WITH TRUE WINTER TIRES AND YOU WON'T REGRET IT!
Need more info? Check out TIRE RACK's helpful website; it's filled with tests, pictures, and customer feedback. This page may help you:
http://www.tirerack.com/tires/tests/winter_perftest_2.jsp
Happy shopping :smile: