You don't say what you want to install.There are some threaded holes on the side walls that I assume are mounting points for seat belts in the passenger version.I have installed D rings for load restraint in my 2016.
There are also metal ribs where you could use self drilling screws for lower strength attachments.Your ply lining is attached to something.It may be best to remove plywood and inspect,depending on what your needs are.
When I was looking at maybe adding some tracks to the 3/4" plywood floor in my 2015 TC, this was the place that seemed to have a good variety. In the end I never did add any and just used the few stock tie downs. But the L track seemed well suited to the light duty needs of the TC as opposed to the heavier duty E track fittings used in full size cargo vans. And the extra strength of the track itself and the screw holes spaced every 4" means the load is spread over numerous fasteners in thin material like was mentioned.
There are lots of cars here with Run flat tires so to allow the spare tire to be deleted. I have not seen a No Spare TC. It could be an EU thing. If you get on a Ford Parts seller with a Manual you should fine all the parts and maybe a listing for the whole assembly.
Hope you find a solution. Let Us Know
New here and have just purchased my very first van, a 2016 1.6TDCi LWB Connect. It has got ply panels fitted in the side recesses and a wood floor over the original van floor.
I want to fit something to the inside sides of the van but have no clue where to start, the ply panels are only 5 or 6mm thick so not sufficient to screw anything to, I'm thinking load restraint tracks but am open to any ideas and advice on how to fit it.
From the outside, it replaces the whole panel. From the inside, there's the fairly large steel door structure that makes the actual opening quite a bit smaller than it appears from outside, as shown in their pics. Desert_Connect has a great photo showing just that in his thread, this pic here: