Yeah, water/meth injection is pretty common mod for forced induction cars to squeeze some more air in there without causing detonation. People often just tap the windshield washer reservoir and use that to hold the meth, since windshield wiper fluid is a more diluted methanol mix you can still use it for your windshield. I personally don't run it because running out of meth on a vehicle that is tuned for it can have disastrous consequences.