Optimizing 6MP Photos For 8' Wall Graphics

I have no ax to grind against any 40+MP digital backs. In fact I welcome any improvements in technology. With that out of the way, I accidentally found some old digital files that was used for an in-store wall graphics for Styletto shoes. Their Makati boutique's wall measured 8 feet high, hence, these images had to be stretched from floor to ceiling. The images were shot by Bug Nieva, and your truly did the RAW conversion, masking and final layout for CMYK printing (circa 2005?). The Fujifinepix S2 Pro was the best 6MP DSLR then when it came to interpolating images to 12MP. I used Fred Miranda's Staire action script to stretch evenmore. Upon visiting their boutique, let me say that the images were good! "Pixellation" is hidden when viewed 3 feet and beyond from the wall! And nobody complained about all our commercial, advertising work with the S2 back then. Today, any 12MP DSLR should out-resolve any old S2 images. But does anyone care? We all should. Occassionally I must remind myself that I ought to shoot and print more often and "pixel-peep" less so we can truly enjoy our passion: photography! Let's not wait till we can afford the next giga-pixelled cam (or FX DSLR, or f2.8 zoom, etcetera). Enjoy it now or never folks.