In my part of the country, we have bad roads, deep ditches, and many creeks and gulleys.
We end up with several vehicles in the ditch, with the driver unfound for several hours or days, and several found dead, overturned in shallow water, or trapped in a narrow ditch, injured, and can't get out.

I've taken to keeping a kit in an insulated nylon lunch bag, the kind with a water bottle on the side and handle on top, and looping the handle throught the seat belt, so that it stays right there, reachable with either hand, padded and not flying around the cabin in a crash or roll over.
I don't think a lunch bag on the seat looks threatening to LEOs, or valuable to a thief.

If your immediate emergency kit is unreachable, behind or under the seat, it might be something the wrecker crew has listed on eBay after they tow your machine.