So, I took my GSR in today to get a wheel stud replaced ($36 parts and labor). Upon doing so, the mechanic caught a coolant leak (heater hose wasn't clamped) which would explain my mysterious coolant loss, thus giving me piece of mind (free of charge). Also, he told me that my RR shock was leaking, thus explains why that assembly was the dirtiest of all the rest.

When I got home, I ordered 4 KYB AGXs to replace all my shocks. I can't wait to get those in!