I was lucky enough to get one with the bass enclosures moulded in. It was on a stand at MG live a couple of years ago. I think the early ones just had the speakers fixed in place, the sealed boxes extend the bass response. On the 1.6 TF the wires are there on a plug so its a10 minute job to swap out and plug in. The wires are the minimum to do the job but for the amount the rear speakers contribute are fine.
I;ve taken the Tbar off here to get to the engine cover bolts easily the moulded boxes occupy all the volume above the front ones. A PO has damaged the theads on those 3 so I prefer to do it this way.
Only aggro is the white "chistmas tree" fasteners which fall off as you snap ther cover back in
And I did treat all that rust while I was there.