I haven't noticed it, but I'm in a relatively dry climate. You can try turning off the A/C a few minutes before you get home -- if it is condensation from the A/C it should mostly be gone by the time you park.
Check out where about it's located under the car. The AC drain (I believe) is at the firewall and slightly to the passenger side of the car. We've been having some really high humidity around here this summer with dewpoints in the 70's and low 80's. I get a quite sizeable puddle under the car after a drive in this.
With the high humidity in SoCal these days, there is a lot of water condensing. Also, ice can form on refrigerant fittings, and will then melt when you stop, causing an apparent "new" drip. Put a paper towel down to catch the drip. On a new (i.e., non-greasy/dirty) engine, it should drip clear and without scent if it is water. Anything else will have a definite oily or sweet scent.
I've owned lots of cars with A/C. At some point in time all of them should have some kind of water drip while parked after the unit has been running. This is especially the case in humid summer weather, but can occur even in dry climates because of ice formation on the system tubing.
I believe that the evaporator is inside the vehicle and the condenser is outside the vehicle. Water condenses on the condenser and when you are parked it all drips off in one place. Consider that water is always condensing on the condenser and while you are driving it is dripping off as you move along.
Actually, the other way around. The evaporator is in the car. It takes heat from the cabin to cause the refrigerant to evaporate. Once that refrigerant reaches the compressor, it is compressed, and sent to the condensor, where it loses the heat to condense to liquid again.
Yes, but the water actually condenses on the evaporator. As air passes over the evaporator, it cools down (duuuhhh), in doing so the water vapor in the air (humidity) looses the energy it needs to remain a gas, so it will condense back into liguid water on the evaporator coils and needs to drain away. This is the same as the central air in your house, on the A coil (which is the evaporator) the water condensesand is drained off into a nearby floor drain.
I was talking to a local mechanic a few years ago and he was telling me of a customer who came in complaining water would leak into his 4X4 when the A/C was on. It took him about 5 min. to hoist it up, and knock the hunk od mud off the A/C drain that was there since his last off-road adventure.