How do you keep your car kit secure?

Neither of my vehicles has a trunk, though many of the security considerations might be similar if they did.

I am going with the: (1) out-of-sight and difficult-to-find-quickly plan for expensive or possibly alarming to the public gear, and (2) out-of-sight under a blanket for bulky and less expenisve stuff, like water.

I am thinking of going to a more secure plan that would let me store a more complete kit, probably in one or more backpacks for potential mobility / bugout. Maybe a metal footlocker secured to the seat mounts?

Your thoughts?

Thanks.