My g/f is looking at buying a 1999 used impreza L with 20k miles one it. However, once you get above 30 mph, you can hear a noise comming from the driver's side mirror mount. I drove it and found I could stop the noise by pressing the seal there against the window.

Basicly my question is... does anyone know if this is a common problem? If so is there an easy fix for this? Also is there anything else we should know before buying this '99 Impreza L.
Thanks