Coupes have a pair of rear deck speakers, a pair rear side speakers, and a pair of front door speakers.

Uh, whatever friend told you there's .5 ohm speakers in anything should be made to wear a gag before saying anythign related to car audio (unless you heard him wrong).

Bose doesn't give out things like "specifications" on its speakers, but any quality amp won't care, as long as they're not 1 ohm or 8 ohm (which they aren't), it will only affect how much power they're able to draw.

Reading what you, yourself have to say:
"put each set of speakers in series to get 1 ohm"

I would hope you forget any ideas you or your .5ohm friend have relating to car audio and go to a real car audio installer before you break something in your car, or cause an electrical fire that burns the thing to a cinder.