Condensation inside headlamps is not a new problem, it's just that the new clear lens headlamps designs highlight what was always there before but not seen. Headlamps, indeed all car lamps front and rear need ventilation to function. As the lamps are switched on the surrounding air heats and expands. The expansion is so great that without ventilation there would be a great risk of failure of the lamp housing, even explosion in extreme cases, and the risk of implosion for the reverse cooling cycle. Due to the need to breathe and the fact that air is humid there is in effect no solution. Lamp design used to be such that the lenses were not clear and nobody noticed condensation before.
Skipton is correct that breather holes and the lights being on for 5 minutes or so should clear the lens but these breather holes are very carefully positioned and sized by lamp manufacturers. Too big a hole in the wrong position could allow water to ingress the lamp during rain or snow and instead of just condensation there could be a flood and the lights fail, too small has as many issues. Also the thermal dynamics of the lamp could be affected meaning that there could be no airflow to the part of the lamp where the condensation is giving no chance of drying out that area.
Lamp manufacturers are spending considerably on finding solutions to this problem and some interesting innovations are on the way, but not for our A2's, not yet any way.
If you drill breather holes in the back of your lamps you may be causing more trouble later. Best take it to a dealer or a specialist if the problem is that bad who can dry them out for you, much safer.
