Hey Everyone, So after double and triple checking other possible leak points, replacing the radiator cap, hoses to overflow tank, etc I did not see any improvement in the amount of coolant leaking. It was a consistent 1/2-3/4 of a cup after each drive. As such, I returned the faulty denso. I was offered a Spectra Replacement, it would have been an additional $80. (Also, I was not aware that all Spectras were pressure tested. Had I known that I would have gladly paid the difference for the guarantee that it would not leak out of the box.) Instead I went with a Koyo Radiator ($40 more) as I have used them in my S2000 as have other's in the community and never had a problem with them, even on track in the Texas heat. Installation was easy (same process as the Denso). Initial impressions are the Koyo quality appears to be better than the Denso. The plastic tanks feel thicker/more robust and the radiator as a whole feels heavier and more solid. After initial startup I am not having any leaks, but I am keeping an eye on it and will report back. While my faulty Denso may have been a fluke, I would not recommend them when there are pressure-tested alternatives that could prevent having to do the job twice.