here I enlarged the inlet port with a dremel n bonded a bigger drain pipe to it
http://micra.org.uk/threads/pollymobiles-rebuild.35251/#post-381100
and here I make a smooth DIY mandrel-bent PVC CAI pipe that feeds from under the gearbox
http://micra.org.uk/threads/pollymobiles-rebuild.35251/page-7#post-412661
joined to the airbox via silicone coupler
at high speed, the fast cool stream of air is rammed into the forward facing funneled pipe and provides a slightly noticable difference in top-end grunt. fitting a bigger scoop funnel further increases the induction pressure.
the downside is the possibility of scooping water during heavy rain but I remember after afew rain sessions, the water spray only appeared up 1/3 of the pipe cos it didn't have enough velocity or volume to reach the filter (tbh most of the content flowing through the pipe is air, unless you literally drive through a river n submerge the pipe) so the KN filter was always dry.
I just avoided roadside puddles and removing the pipe as a precaution was as easy as undoing the coupling and pull it out.
