I love the field-abandoned exhaust tubing and muffler in that photo.
With regard to cell mounting, wait until you get the cell so you can measure it, then start googling fuel cell mounting on this forum. There are a lot of photos of how other teams have mounted them and passed tech. Basically, you'll build a separate cage to hold the cell, and then that cage mounts to the car in the trunk area. There are some very specific rules requirements that you have to follow when using a fuel cell, so make sure to read and follow those rules so that you pass tech.
My handy hint on all of this is to let somebody else make the stainless-braided lines that you will need. I've found it difficult to get those lines leakproof if I try to make them myself, and there are lots of line-building services out there that don't charge a lot to make them to your specification. On the pressure side, I always have somebody else build those now, that's not the place to cheap out and suffer a small leak that will get you kicked out of the race.
Pat Mulry, TARP Racing #67
Mandatory disclaimer: all opinions expressed are mine alone & not those of 24HOL, its mgmt, sponsors, etc.