I put general altimax arctics on my BMW 530 and it made a world of difference. They weren't that expensive either. Great tire. I try not to drive this car when it's snowing but I had to a few times. Being rwd, this car would get the rear end squirrely in a hurry with All-Season tires, but not with the arctics. But more importantly, it would stop when I had to stop. Now granted, it's not AWD like the Subie is, but if your son is going to be heading to the Mountains, I would do it.