Looking under the seating console in my S3.45, I've thought several times that it would be a nifty spot to store a fuel cell, but it would need to be purpose built for the spot.
This morning, lo and behold, I run across this page:
Which seems to indicate that the S3.45 offers this "Under rear seat fuel tank stowage" as a special feature.
Does anyone have any knowledge of such a fuel tank, and if so, I am very curious about the details of it... I sure would love to get the big ugly red poly tank off the back deck and make room for gear or passengers....