(1) I bought 2 pieces of flexible 2"
aluminum carburator pre-heater hose and joined them together by applying some
epoxy and "screwing" the two hoses together (when the hoses are
stretched, they possess a thread like surface)
(2) Drill or cut a 2" hole in the plastic splash guard in front and below where the sway bar pokes through.
(3) Feed the hose down in front of the air filter
box and in front of the sway bar. Then, feed the end of the hose through the
hole in the splash guard enough to have the hose dip down into the flow of air
under the miata.
(4) Stretch the other end up towards the intake snorkel. At this point you can either attach the hose directly to the snorkel or simply near the snorkel. I've tried both ways and a direct attachment seems to work better. No apparent problems with it being restrictive on the intake.
(5) Once the hose is in position,
use several wire ties to hold it all in place. I "piggy-backed"
several around the hose at the splash guard to keep it from pulling through.
(6) Angle the input side of the hose so that you can just barely see it while sitting in front of the car. This will cause the air to push its way up as the car moves, compensating (hopefully) for any flow restrictions contributed by adding this hose to the intake.