Water injection WORKS.
Built a prototype system in about 30 minutes. Keep in mind I'm Series1, with an M62 blower that could NEVER reach full boost. With the increased intake density and cooler air caused by the water injection, I'm hitting the hashmarks on the gauge.
Prototype 1 was a simple siphon system with a 1/2 pint water tank.
Prototype 2 will draw regulated (@5psi) air from my spare tire, and feed from a small pressurized water tank in the trunk. I'm building it right now. I should be able to do more in-depth testing with this system, with a full pint of water.
If this works out, my final system will be solonoid controlled with a 1-2 gallon tank.