I am in search for BA-6 interior pictures. can someone point me to any books/magazines in which I could find them?
Thanks in advance.

If you do some deep digging on the net I know you will find pics ....I have the Zvezda kit waiting to be built and have been compiling data. Tamiya magazine(Issue144 Oct 2007) has a really good article on the kit with intirior upgrades visible in pics. They also show the upgraded radiator and louvres which I thought was pretty neat. I will do some more digging for you.

Have you seen this?
http://www.armchairgeneral.com/rkkaww2/galleries/armored_cars/BA_6.htm
this is the only interior picture I have been able to find. Is from a Militaria book (Wydawnictwo Militaria256: Sowieckie samochody pancerne vol II) Plenty of other Russian armored cars interior pics inside but only this one of the BA-6:

Plenty of interior shots of the BA-3 here:
BA-3 Interior

Not sure how much difference between the two interiors, but you maybe able to use them.

Thanks , they look similar. Both used GAZ AAA trucks as base with small development differences so most of the vehicle should look the same.