Most aveos came ac ready. So you most likely have the evaporator in the dash. This sounds like it was water rushing into the fresh air intake for the vent system which is in your rain tray. Car washes have a way of putting water will it will not normally go even when driving 65mph in the rain. I had an audi tt that would leak like crazy in the high pressure car washes.

I would possibly check to see if there is a problem within the rain tray. But I would just not use the car wash and see if it ever happens again under normal conditions