Thanks for all the helpful answers which has at least reassured me my 370 is not the only one without a jack and handle, but at least the foam cut-outs are there for them.
From the handbook you get the impression you squeeze the sealant in and then start the pump but it then says if the tyre does does not start inflating as the hole is not sealed to call Nissan service - very helpful, I think not. Just make sure the breakdown cover is up to date.
As there is easily room for a spacesaver wheel and the handbook indicates the sub-woofer will fit inside that as it does refer to that combination, so that will be my favoured option.
So jack, handle and spacesaver wheel on the list.
And dawg, you don't get your bone tonight