I just installed the same heater into my brothers 2007 Corolla, it was his Christmas present

. I didn't have the camera and it was quite cold outside when I installed it

. I really think the plug housing is a great idea, I may have to give his vehicle the treatment.
To cut to the chase, any Toyota owners that want to find their OEM option block heater part numbers can find them in the attached Jpg Files... Hope that helps, I know I found it useful.
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