Why is my Porsche 997 dripping colourless fluid underneath after driving?

The most likely explanation is that it is from the air conditioning and nothing to worry about.

However, it is worth putting your hand in the fluid to check what it is. If it’s just water, then it is almost certainly a normal byproduct of using the aircon.

There is a chance it is coolant, which could be a sign of a leaking pipe and would require further investigation.