mine has got.... (from memory)
about 1L of OAT in the bottom of the 5L container, a selection of screwdrivers, spare bulb set, latex gloves (slightly used) high viz jacket... all those above/level with the boot lining, next to the 'dead space' around the wheel arches...
underneath - warning triangle, 1st aid kit, torch (tho taken out as batteries dead) de icer, emergency screenwash, few spare fuses to compliment the ones in the car, can of foam (probably out of date now), safety glasses.... and no water
- that is in my drivers footwell