Installation suggestion

Hey guys, I was in the middle of my wiring job when I decided, while everything is out I might as well add the things that I wanted. One of the things I wanted to add was a fuel shut off valve, I would've liked to add if for security purposes.
I first wanted to add an electrical one that would be controlled by a switch but that idea doesn't seem to be working out very well, all the ones that I find are absolutely huge. So, a manual one, I was wondering if there was a way to install it with the teh lever being on the inside, like under the seat or something, u just push it while getting out and pull it before u start up the car?
Or where would you guys install it?

hmm, ic, I have hood locks on the car, but it would be a dead give away if some1 was watching me open up the hood and turn the valve.

I was also thinking about installing the T-lock shifter, its baisically a shifter that looks like the stock one but on the passenger side has a lock instead of a black thing coming out. When locked, the car cannot be shifted out of park. The only problem, is that the company who makes is completely out of touch, not responding to people's emails nothing... and there's no phone #.

as for the grant security... i'm still kinda hesitant on that one, I just bought a new repo steering wheel, (99$ at california mustang, everywhere else it was a lot more)

Right now: i have hood locks, and i used to have an alarm system, but I ripped it out when wiring and I don't think i'll put the same one back in. It was a simple one that ran off of vibration, I'd like to up it some more and have it also connect to the door jab switches so when you open the doors or the trunk (i'm installing a door jab switch in the trunk for lighting) it'll go off if the alarm is still on.

Edit: I was wondering on the alarm system came this little push button which lead to teh box... anyone know what that is for?