I like the idea of a Nalgene kit for the car, along with a blanket, as a minimal kit.

The little orange bag that the Heatsheet comes in to carry the smaller gear later on.
A Ritter PSP and an AMK Pocket Medic, both removed from thier respective pouches, less the mirror, aluminum foil, frensel lense and the duct tape (they just don't fit).
A bottle of PA
A metal cup under the bottom of the bottle
Photon or similar
Vic Huntsman SAK
hotspark or similiar
2x 3x3 gauze pads (or 4x4s if I can make them fit)
mini bic with a zip tie under the plunger
duct tape wrapped around the bottle (replaces what is lost from the PSK)
a few more tinder quiks
a spool of waxed dental floss
6 or so zipties
two or three 20s, and some quarters
A minibinier with a couple of spare split rings, clipped to the cover strap, to attach the hot spark, Photon and whistle to the SAK after the kit gets opened, and to anchor it in the car to an unused seatbelt, back of the passenger headrest or similiar point
A spare watch cap pulled over the whole thing

If I'm allowed a pouch I'd also want the metal top of a carefully opened coffee can (lid for the cup), the mirror, foil and frensel lens along the bottom. Maybe a coil of line (probably Triptease or of similiar weight).

Alternatively, I might try the rectangular Nalgene. Easier to pack the flat, wide items if it is in a pouch, but with the aluminum foil returned as I've never found a tin that will fit the bottom of this thing properly. If I did that, I would really want a couple of 4x4s in a freezer bag.