Just take a look here, it explains where it is located http://repairpal.com/where-is-cabin-air-filter-located-040, than check for more details here http://us.lexusownersclub.com/forums/index.php?showtopic=43521. If you have to order cabin filter, notice that they are two pieces. One thinly which is on the top of the slot, which you will find behind the accelerator, and one at the bottom of that slot. Pretty interesting solution. I had to think a lot until I got the solution hot to put both filters in the thinly slot. I ordered the es300 3 weeks ago and I had no cabin filter in it. I had no idea how to mount them. Today I found it. Good luck!