"I want to make ALL of my vehicles able to accomodate DAZ figures ideally - and I want them useable in all three apps (Bryce, DAZ S, and POSER "n". "

Hi Mugsey:-)

A suggestion: Export one of the DAZ figures (the one with lowest poly-count you can find) as a .obj and use it as a mannequin to keep the scale between different vehicles consistent.

I tend to use 2 or 3 poses for my models, depending on what I'm going for.
For clothing I use the zero position.

For something like your craft, I'd do "standing" and "sitting" poses, too.

Import the .obj (one or all, depending - or swap them about).

I don't know if Wings has a "decimate" function (which allows you to dramatically reduce the poly-count whilst still keeping the general shape), but if it does use it on the mannequins with a vengeance; they still look recongnisable at 1/3 the number of polys.

Don't forget that Poser's scale is tiny. You'll probably have to scale up by at least a factor of 100 on import.... Just don't forget to scale back down again when exporting out of Wings.

Cheers,
Diolma