Use a combination of johnsons baby shampoo and water in a spray bottle. Then use a hand held squegee to slowly press the water out, pressing the bubbles out as it goes.
Then any bubbles that are left can be popped with a needle... Dont laugh, its the way the pros do it...
Yeah, if you ever see someone tint, they do the same thing. The guy who tinted mine even used one of those sheet things you put with clothes in the dryer - he told me it gets rid of all the static electricity so its easier. Thats might be something you might want to try too.
i wouldn't recommend windex. if you dont work fast enough, it will eat away the glue on the vinyl. go with the first post. water and just a little soap in a spray bottle. make sure the surface is clean by rubbing it with alcohol.