Mine has the same problem for now. It is probably caused by the upper spring mounts. It is a plastic spring isolator. You can switch to a bearing type from say Steeda. This should get rid of that annoying popping. This is what I'm going to use.
My 03 used to do this as well and it was the upper strut mount bushing. It had flattened out so the strut was banging around in the tower. Hard to see when just looking under the hood but my mechanic found it. My 08 isnt doing this (yet).
The problem as far as I understand is the plastic upper strut mount. If it is still popping after being replaced with something besides the factory piece, I would look elsewhere for the problem. Sorry I have no other guesses.
Hmmm, when I first back out of the garage or a parking space, and turn to the left while letting out the clutch slooowly, I hear a popping/clicking that I feel is coming from the pressure plate or CSC. Only seems to happen at that time. Not sure this is what others are hearing.