New custom made top mount:
cost $800 from Adrad here in Adelaide. Slightly heavier than stock, but much more flow area and the inner tube and fin arrangement is impressive.
Yes i could have got a chinese made FMIC for cheaper, but the cost of doing one properly, that holds up to inspection, is simply too much. Besides, i'm building the car as a Grand Tourer, not a racer.
Oh, and if you don't have one, get a 12mm ratchet ring spanner (you know, a ring spanner with a ratchet action like a socket ). Makes installing and removing the 4 bolts at the throttlebody a breeze.