I know a lot are drilling a tiny hole in the outlet elbows bottom in the Cac. It will drain build up but not the water sticking to the tubes. It is a somewhat fix after out of warranty for sure. Start with the smallest drill bit and work up to UR happy. It may whistle some if too large say near 1/8" so stay smaller say near 1/16". The iridium spark plugs are just too flimsy, I would use double platinum myself. Have always changed out to double platinum. The iridiums no mater what the mileage go to the shudder going down the expressway up slight inclines stretching out say 1/2 mile or more sooner or later and this also damages the Caps associated to the weak plug.
I would suggest drilling a fairly large hole in the lowest point of the CAC outflow endcap. Large enough to fit, epoxy in a 1.4" copper tube that will accept a section of standard automotive rubber vacuum tubing. Put a lawn tractor fuel filter inline with the hose, and then another section of 1/4 copper pipe. fill one end of that copper tube with solder, the use another section of rubber to connect to a spare fitting to the intake manifold downstream of the throttle plate.
Next is a bit of trial and error.
Purchased at 30,000 miles my '95 LS400 had a cold start high idle of about 12-1400 RPM, pretty serious JERK slipping it into gear at those idle speeds. The 95 had an IACV with a rubber hose feeding the input so I inserted an airflow restriction in that hose to restrict the available idle airflow to just enough to reach ~800 RPM.
I "hid" a copper tube filled with solder inside the hose feeding the IACV, drilled larger and larger holes into the solder blockage until getting to 800 RPM maximum idle.
With the EcoBUST engine you will want to have just enough airflow through the restriction to support HOT/low idle RPM. The engine ECU will do the rest, it will "learn" to adjust the DBW throttle plate to get high idle with cold starts.
The only reason for the inline fuel filter is to prevent the smallish aperture you drill in the solder blockage from getting clogged.
Oh, 280,000 trouble free miles on the LS....