I want to pick up some Hyrdo2 for my wheels. I was going to get the 100ml bottle but I won't have enough to do a proper dilution of 4:1 with a 32 ounce spray bottle. What size spray bottle should I get? Car Pro says to dilute 4:1 which would be about 6.5 ounces of Hydro2 correct (if I use 32 ounc bottle). Are you guys typically buying the half liter?