Perhaps, a modern Toyota does have this option. My 4Runner definitely does not turn off the AC. It specifically states in the manual the most efficient heating method is to have the AC off.

Just because it's the "most efficient heating method" doesn't mean that it's the most effective solution over all. In a snowy climate, when your boots are snow covered or wet when you get in the car, heating the car cabin isn't the only consideration. You want to keep the windows from getting fogged up. Turning off the A/C to heat the cabin quicker is not going to address this issue.

What does it say about dehumidifying? Again, if you need to do more than just put out heat, then "best results" are relative.

I strongly recommend this for effective windshield defogging. If the A/C compressor is operated in the defog cycle without some added heat, the cold air from the compressor will chill down the windshield and cause moisture-condensation on the outside, which the wipers will then have to clear. Adding heat to the A/C, as Jill says, will dry out the inside air very rapidly, allowing it to effectively clear off and evaporate the moisture on the inside of the windshield. You don't have to add a lot of heat to the A/C in warm humid weather, which would make it uncomfortable for the occupants inside...just a little heat, or enough to do the job. But don't run full-cold A/C on the windshield to defog it..... that's just asking for trouble.

OK, no problem. I didn't notice that, but I'm not in competition with anybody here....no trying to be. We're all here to help and advise each other. In fact, that's why, years ago, the automakers started modifying the A/C systems to allow heat to be added to the cold air blowing out. When they first started linking the compressor-use to the defog/defrost mode, without the ability to add heat, people were ****ing-up the window glass with outside moisture-condensation. I remember that was a problem in my late Mom's old 1977 Plymouth Volare.....though the very definition of the Volare/Aspen was problems LOL. :D

What I'd like to see is the ability to vary not only the amount and intensity of air-flow through the vents, but also to be able, in warm humid summer weather, to direct warmed/A/C air through the defrost vents for defogging, and, at the same time, have cool air coming out at face-level, in the dash-vents, for driver/passenger comfort. . I don't know if you have that on your LS460 or not, but no car I've owned yet (including the Lacrosse) allows that. It's all the same temperature, no matter which vents you use.