Possible to do in a BA falcon, using stock speaker locations???
My biggest drama is not being able to angle the mids, as there isnt much room behind the trims. Hoping I can get the tweeter mounted in a coaxial type setup, if room allows, so I can get some kind of angling happen. But yeah, anyone managed to get a BA imaging and staging half decently, or even using the factory spots on something like an EF/EL. They seem to be similar locations. Time alignment is not allowed in this either.

Since you have several installation limitations, it will come down to speaker selection. You will want to choose some speakers that have a fairly smooth response when off axis. The difficulty when selecting them, is if you listen to them on axis (in the shop) it is possible that they may sound a little harsher than they will be when mounted off axis... Is equalization an option?

yup, equalization is an option.
Although I've already bought the speakers. Judging by the fq response graph of the dyn's, they dont seem to be that bad off axis.
Can decent imaging be had by only angling the tweeter, and not the mid?

edit - I should say exactly what I'm after. I'm not so concerned about instruments sounding like they're in the correct place and all that. I just like my music comming from dash height.

for exelent off axis response, have a look at the Adire Koda splits

Yes can be done. I have an EL that images and stages reasonably well with 4" mid in the factory location. It is mounted on a MDF ring and angled as much as i could which is probably only 15 degreeds or so.