Great question, I recently purchased my Extreme 360 and notice the belt cover rubbing on the underside of the bonnet, was going to modify the cover so its closer to the belt, and create more clearance seems easier than messing with engine mounts.
There's not much room under the bonnet, personally I think thats a quite a topic, optimising the space, getting the air to circulate, getting cool air into the intake whilst keeping the bonnet from getting hot (eg with reflect-a-gold or something?). I've temp fitted a K&N type airfilter and even that is right up against the bonnet underside.
What have others done?