Lexus RX300 Manual page 154

(c) Air filter
The air filter may clog after long use and reduce air flow. You can
inspect the filter easily.
When you inspect and replace the air filter, be sure to turn off the fan.
21R040a
1. Open the glovebox and remove the two covers.
AIR CONDITIONING AND AUDIO
21R041a
2. Take out the air filter.
If it is dirty, it should be replaced. To maintain the air conditioning
efficiency, replace the air filter according to the maintenance
schedule. (For scheduled maintenance information, please refer to
the separate "Owner 's Manual Supplement/Maintenance
Schedule".)
NOTICE
Do not drive with the air filter removed, or the efficiency of air
conditioning may be lost.
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