I took the spare off my Plus Four to check the usable space. There is a plastic panel beneath the wheel that seals off the space underneath. It’s held in place by ( if I remember correctly) by about4(?) bolts. The panel is a tight fit under the body panel edges so not the easiest to remove. I was refitting the Cobra(high) brake light at the same time so needed access to the wiring connector. I managed it by carefully moving and bending the plastic panel enough without removing it. I don’t know how much actual space is under there.
There is a spec option to have a lockable storage in the rear of the shelf area. Not very big though.
Also, there are stuck on panels in the chassis vertical panel below the rear shelf. The carpet is easily moved. Anyone know what’s behind them? I suspect the sound system amp might be in one side. If the other is empty then that might make a mod an option, and fairly easy to access with the seat forward. Photos of the chassis from the factory show these panels.
