Not just the ol spaghetti jets either, HQ and onwards in the Holden's, XA and onwards in the Fords.
You sort of expect, or at least hope, the designers would've considered those plenums would trap a bit of dirt and leaves and crap.
Agreed.
Had an XB van for 13 years. The plenum wasn't a problem on mine.
The issue was crud from the road and the plenum got trapped behind the bottom/rear of the front guards.
Had a CM wagon for 13 years. The only rust in it was a couple of very small bubbles in the tail gate.
Have seen plenty of them with holes in the plenum though.
I regret selling both of them, but at the time had nowhere to keep them.