Holy floor pan (in a good way)

[Marineboy]

Hi all

Strange question and one that show my lack of knowledge, but does anyone know what the various holes on the underside of the floor pan are there for?  I get that there may be redundant alternative mounts for different models and the like (e.g. alt exhaust hanger pic attached pic-1) but I’m just interested in the larger round and elliptical holes (pic- 2 and 3) and smaller holes at the ends of the stamped strengthening channels (pic-4 and 5).  I’m guessing some holes might be grab points used to align the panel by machine for assembly etc.  Just wondering if anyone knew?

This is the other half’s 2008 KA as a matter of interest.

[Luke4efc]

I always thought they were for holding the chassis in a jig for lining up and welding the body together. Perhaps maybe for supporting it for painting too? 

Suppose they also act as a water drain too.

[Marineboy]

Think you might be right.  Not sure if these sorts of things are water drain provision though.  There are also probably deliberate tiny holes where a box section is welded and forms a completely enclosed void (gases, expansion etc) as well, but I've not noticed any.