I JUST bought a 1988 735i 5-speed this morning. On the ride from Philly to DC, the windows stopped working (they had worked earlier in the trip). I called the previous owner and he said that the problem occurs when it's cold outside, and is always intermittent, not permanant. All of the window switches are affected (even the ones in the back). Could this be a relay problem? If not - does anyone have an idea of what it could be?