Next task is to fit my floor and rear bulkhead panels. I am using alu - 3mm for the floor - 2mm for the rear bulkhead - and will be using sikaflex/tigerseal and rivets.

Having tried to 'dry fit' the rear bulkhead - it's obvious that some of the welds where the tunnel meets the diff foul the panel and stop it sitting perfectly flush. I am loathe to grind back those welds given the importance of strength in the chassis.

Do I trim the panel to accomodate the welds - then use trim to cover up any small gaps?

Or do I use alu panel which is 'full size' but thin enough to flex over the welds where necessary?

Your practical experiences and advice is appreciated as always!!!

I used 1.5mm thick ally and used a rubber mallet/small hammer over any welds. A bead of Sikaflex on the chassis before final fitting will seal the panel and add strength.

I'd use thinner ally and shape it over the welds. 3mm floor and 2mm for the rest is pretty thick. Think mine are 2 + 1.5 and thats more common.

I'll go 1.5mm on everything except the floor then. I've got a big sheet of 3mm for free - if you haven't seen in other threads i'm the 'using the pub sign for my floor' man :-D Photo evidence here: http://meandthekitcar.wordpress.com/2013/08/18/floored-pt-3/