Thanks for the quick replies! I didn’t think to look at the old filter when I took it out; just tossed it. The downward direction seemed intuitive to me, and that’s the way I had installed it. It is downward in my Honda CRV. The Lexus manual is not so obvious, it says something about an ‘arrow’ that is printed on the Lexus replacement filter, and that arrow points up. No mention of airflow direction, though.