I was getting ready to do water pump #2 on my XKR (dealer replaced in 2015), but before ordering parts I was poking around and noticed that the coolant overflow line that runs from a couple connections at the front top of the engine back to the expansion tank had a slight split in it. The split was located right where the line was secured to a bracket directly in front of the oil filter. It was drip a small amount of coolant which would run down the front of the engine right near the water pump, hence my original water pump diagnosis.
I ordered a new coolant line (part # C2P13304) and changed it out in about 20 minutes (the front lower connection on the XKR is difficult to get your hand on, but it's do-able). I also dropped the under tray and gave it a good cleaning. No coolant smell since.

This image isn't great at helping identify, but just trace the line from the connection at your expansion tank and give it a careful inspection for cracks. Mine was very brittle and easily broke in a couple places when I pulled it off the car.