I made a bracket for a fire extinguisher under the passenger's seat. Here's an album of the build/installation: Imgur: The most awesome images on the Internet. I'm not arguing this is the best place to put one, but it's reasonably easy to get at from the driver's seat. I tested clearances with the seat back in and it's all good. There's a surprising amount of room under there.

 

Looks good and an excellent reminder for me to install mine.

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Very nice and good pictures! Thanks for posting.