What causes a 2000 Ford Focus Se to fishtail in snow?

Answer 1

for some reason lots of Ford focus 2000 station wagonsafer from this problem, it was fishtailing even on dry surfaces when my tire hit little crack in the road (like crack between concrete on highway) on my ford because previous owner did not pay attention. I replaced front and rear strut both lower arms with ball joints and both front stabilizer links, perform professional alignment and with every step it was getting worst and worst because it was loosing possibility for play. I can not say that after all my car did not benefit from all job that was done. after eliminating possible cause one by one I end up replacing rubber (tires) because when i rotate my tires it change fishtailing effect (increase or decrease in different places), and this finely solve my problem.