I wanted to take a few moments to post my experiences with the Viper/Emgo fairing...
For quite some time I have liked the look of the Viper fairing and I have thought of having one on one of my cafe bikes. Unfortunately, after reading Forchetto's post about the Viper fairing not fitting I was a little discouraged. Forchetto seemed convinced that you could not make one fit. However, when Dave, Mike and my friend Dan and I went to the Barber Festival, we saw an older Bonneville with one of the fairings, I just knew I had to have one. I loved the look, and I'm stubborn that way. I knew I could make it work.
So I ordered one and proceeded to attempt to mount it on my Bonneville. I bought it for about $70 including shipping. The entire fairing was of above average constrution for the price I paid. However, I did go down to the local hardware store and purchase all stainless hardware and rubber washers where the bolts went through the plastic. It came with the fairing and the plexiglass shield separate, and the bolts to connect the two had two rubber washers, and only one metal washer, so I bought an extra stainless washer for each one. Every rubber washer needs a metal washer on top of it. I also purchased more flat fender washers and rubber washers to bolt the fairing to the brackets. I also purchased Nyloc stainless nuts, so I wouldn't have to worry about anything vibrating off. All of this only cost a few dollars and was well worth the extra time and effort.
First off I will say that I don't think it will fit with the stock Bonneville handlebars. I had Harley-Davidson Nightster bars on mine, but they were too high, so I swapped them out with some Harley-Davidson Sportster bars that I had laying around the garage that were lower and a bit narrower. I actually like them better. It gives me a little sportier riding position that is just as comfortable, if not more comfortable than before.
The fairing comes with some bent flat bars that have some slots in them. These needed to be bent some more and formed to fit the headlight and the fairing. It took a bit or trial and error, but it was pretty easy. I ended up using them and some longer stainless bolts that I already had in my headlight brackets for my Triumph Thruxton fairing that I had on my bike.
I happen to think I came out looking really well. As a matter of fact I love the look and the functionality, however; I waited to post anthing about it until I rode with it on my bike for a while. As I type this I have put over 300 miles on the bike with the new fairing, and I can attest to the fact that it cuts through the wind nicely, at well over 100mph. [On a controlled road with a professional driver of course

]. I does a good job of keeping the wind off my chest, but allowing clean air to hit my helmet. For my riding style, I don't think I could ask for a better fairing.
By now you have obviously noticed the wire mesh over the headlight. Maydaymike gave that to me at the Barber Vintage party. He said that it and the little clips were for a Mini Cooper and I was going to put it on my headlight, but after I mounted the fairing, I decided to drill some holes in the fairing and mount it to the fairing instead of my Bonneville headlight. I thought it worked out well, and I kind of like the way it looks on there.
As the fairing is delivered, it is only intended to be mounted to the headlight bolts, but that was not good enough for me. I think that any decent fairing should be mounted to at least 3 points. So I had the bracket from my Thruxton windscreen that bolts to the rectifier, and I decided to keep that and i fabricated an additional piece of aluminum bar to restrain the fairing at the bottom.
Here's a picture lookng at the headlight brackets...
Here's a picture looking at the handlebars and the back side of the fairing and the tight clearances at the clutch and the brake master cylinder. The clearnances are tight, but there is no vibrating at well over 100mph, everything is very sound and sturdy...
So in conclusion, I would highly recommend this fairing. I think it added a great deal of functionality to my Bonneville, it looks like it was made for my bike, and most importantly I like it a lot.