How can you tell if your GS 450 has this?

 

You can read a little about it on this techinfo page from Toyota. It's the part on "Low Voltage Batteries" and is on page #12 of the document, or page #15 of the file. There are 3 pics on that page. In the right most pic, it's the system occupying the spare tire, next to its own little battery. I will try to take a pic of it.

https://techinfo.toyota.com/techInfo...ocs/gs450h.pdf

 

Look in your trunk if there is a motor than you have it if you not you dont!

 

Here's a pic of the **** motor and its battery (lower right) occupying the whole spare space.