The bare minimum?
 

From everything I've read on the FR-S, it seems that the engineers got pretty creative with making the car as light weight as possible based on their budget.

I just emptied my old Honda Fit, traded for a soon to be delivered FR-S, and I cannot believe how much useless crap I took out of the Fit. Way too much weight just sitting there doing nothing. I like to pack some basics in case of an accident/emergency but I'd like your opinion on how little I actually need.

1. Leatherman tool- for basic tools for repair or cutting a seat belt etc.

2. Tire repair - seals a tire blowout so you can get to the nearest help

3. Maybe a Cliff bar or basic food item if I get stuck somewhere

4. Small bottle of water for emergency

Any other must haves? Thanks :)

Hot chick in the passenger seat! Should be easy with a looker like the 86!

On every-day drives my BRZ has in it:
Owner's manual packet (for quick reference)
Phone charger
Sun shield (for parking at work)
Ratchet/Screwdriver set (just in case)
Folding Subaru cargo container (very useful)

It also has a folding chair in it at the moment for meets, but it won't stay in there.

Don't need any of that shit unless you're going rural, phone will do. Get a light weight one. :)

You seem like a bit of a boy scout. I mean that in a good (be prepared) kind of way. With the items you already have listed, a small and simple first aid kit sounds good as well. I think I remember reading somewhere that this car comes with one, but then seeing it on the accessories list. Can anyone confirm if the car does or doesn't come with a 1st aid kit?
Unless you plan on ditching the spare tire, I wouldn't bother with the tire repair kit. They are pretty much useless for all but the smallest punctures (like a nail or screw).

mine came with a first aid kit in the glove box

My owner's manual folder/case thingy has the first-aid pouch built into it. Has scissors, some gauze, tape, and a few bandages in it. Really basic, but useful.

I just keep a couple wrenches, the spare tire, jack, and my custom socket and torque wrench for my aftermarket lug nuts.

On a new car don't think you need anything besides the spare and tools in the trunk, at most I would add a roll of duck tape.