Although I do not have snow tires on my Contour, I had a set of 205/60R15's on my last car and now on my current winter car have 185/65R14's. On both sets have I driven 100mph, but just for a shprt time. However, I have sustained 80mph on the 205's for 2 hours without blistering.
Noises are no problem, vibration is. If you only hear a noise, then you should be fine.
