Lexus GS300 1998 Owner's Manual page 221

AIR CONDITIONING AND AUDIO
(d) Operating tips
D Make sure the air inlet grilles in front of the windshield are
not blocked by leaves or other obstructions.
D If air flow control is not satisfactory, check the dashboard
vents. (See "Center vents", "Side vents", "Lower vent"
and "Rear vents".)
D To help cool down the interior after parking in the hot sun,
drive for the first few minutes with the windows open.
After the excess heat has blown away, close the windows.
D When driving on dusty roads, close all windows. If dust
thrown up by the vehicle is still drawn into the vehicle after
closing the windows, it is recommended that the air intake
control button be left to the OUTSIDE AIR mode and the
fan speed control button be pressed to anywhere except the
"OFF" button.
D If following another vehicle on a dusty road, or driving in
windy and dusty conditions, it is recommended that the air
intake control button be temporarily pressed in to the
RECIRCULATED AIR mode, which will close off the
outside passage and prevent outside air and dust from
entering the vehicle interior.
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