I think your front right water intercooler leaks. this is a common problem with the 996 911 turbo and I think as well with the 4s. The cooling water from the engine goes through hoses to the front and there through aluminum coolers back to the engine.
The problem now is, when you are driving every day, that not much is coming out when the car just stands still between eacht drive for a night or some 24 hours. The cooler leaks normaly not much and only when the water gets hot and the system is under pressure, normally while driving. But while driving the vans blow the leaking, dropping water anyways away in front. You won't ever see any thing or smell.
If my car stays for some days, some drops of cooling liquid which is a bit sticky indeed, is laying under the right front of my car. And I'm loosing around a liter of cooling liquide per month. - I'm under warranty, and my cooling system gets fixed, till then I'm having an eye on the cooling liquid and refill a bit if it's needed.