I like to leave the tranny tunnel exposed, comes in handy for a quick inspection, refix handbrake switch or speedo cable or adjust handbrake.

Personal choice though.....AndyH

That was more or less my thinking Andy :)

I also felt it would be a nice collector of every lump of garbage that comes its way ;)

when fitting the rear ali for where the seats are. do u just cut to size and pop rivet as it is, or do you have to do something to the edges (clean them up/round them or sumit)

Cut the sheet so it's just shy of the radius on the tube so when it's on you won't have a sharp edge.

I'm going to do the floor, sides, rear panel (and maybe bonnet) in ali, so how many sheets of what size and grade will i need?

3 sheets without bonnet. 4 with. there will be enough to make a fuel tank out of that too.

So that would be 3 sheets of say 1.0mm (sides rear, bonnet) and 1 of 2.0mm (floor)

when I get as far as the ali for the tunnel my plan was going to be, get some bolts and weld the pointing down on the inner edge of the tunnel and allow the ali floor to run on say 15mm so they are poking through hole's then make a piece of ali the same size as the tunnel and drill holes in in so the bolts come though to hold it up and then use nylock nuts and cut all the bolts so they don't sit proud. This way the prop is covered but with a few bolts your in and able to work on things

For covering the bottom of the tranny tunnel, separately, the best thing is just to drill a few rivnuts and use button head bolts.

Only problem with that way they could work loose over time and one day your driving along and hear a scraping noise. With the nylock nuts they won't undo on you and cause you grief.