We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember Adrian Brentnall
saying something like:

So - is there some kind of a plastic fixing that snaps into these holes
to accomodate a screw or somesuch - or do people generally just whack
self-tappers into the inner panels ?

I've done it with STs before and it works ok, but beware of stressing
the mounting points too much if you're hanging gear off the lining.

Anybody done this before & have words of wisdom to share ?

FFS, don't screw the floor down without carefully checking clearances
underneat. A screw through a fuel, brake line or fuel tank can ruin your
day cough. For this reason I decided the next one I do will be lined
with plywood glued in place with gobs of polyurethane foam.