Any factory window glass, or factory replacement glass, on your A4 is coded with a manufacture date. In one of the bottom corners there should be manufactuer information. Look at the last line. There should be a single digit and some small dots. The digit (e.g., 7) indicates the year (1987), and the dots probably indicate the month (5 dots = May). I'm not postitive on the dot part, because I haven't seen one yet with more than about 7 or 8 dots.<p>So, if your glass has been replaced, you, or someone "in the know" can tell.

Yes, all the glass will fall out, the steering wheel will lock up, the sunroof will open, and the drivers seat will be ejected at exactly 12:01am, 1-Jan-00, regardless of what time the clock is set to. The car JUST KNOWS.