I got a tiny little one and managed to fit it under the clocks cover on the zx9r C model, it sits at the bottom of the speedo.
I then wired the negative to the neutral earth, as its switched it would only come on when the bike was in neutral and the ignition on, that way you can see the battery voltage, and then the engine running voltage before you set off and then the most of the time its not shining in your face.
Only saying this to give other ideas.
On the zx-12r I have a acumen dgv - digital gear and voltage indicator but have a switch to turn off the voltmeter when I want. Thinking about it now I should of wired that up the same mebbies.
For Tech Questions Bike Model letters are more useful than saying the year, for uk owners anyway, as registration year is not always year of manufacturer model.