Right side front frame member. You see, Road Gremlins are all left-handed... so putting it on the right side, as low as possible, really messes them up... and they fall right off!
I have one that was given to me in 2008 on my old '95 Evo Police Special E-Glide that has worked very nicely - saved my ass in a tight spot on the highway last year when an IDIOT in a Tahoe jumped into my lane without warning to make a left turn from the RIGHT lane. Well, that and the big 4-pot front calipers!
I'm still waiting for my current riding group to gift me with one on the new '12 CVO SG... hope they don't wait too long... but it's bad luck to ask for one!