It looks like the bike was designed to have the rear brake cable and air box to take up the same space. I tried re-routing the cable, but there really isnt' anywhere it will fit or won't flop around and hang into moving parts. I tried filing down the side of the airbox, but I filed a hole into it and it still doesn't have enough space to clear. I noticed that the cable hits the part of the engine case that a rear motor mount bolt threads into on the left side of the engine. I'm starting to think that there's a chance that it's the wrong airbox, but it appears to fit just right in the compartment, with the exeption of the brake cable blocking it. The airbox says "Gilera" on it. Did Gilera make the airboxes for vespa or is it the wrong airbox and someone just robbed it off of a gilera moped?