Base '06 vrs 04 limited with fewer miles?? comeon the cars are essentialy the same year to year. 81k is when fan motors and little annoying lights start vexing your driving fun.
Go for the '04, enjoy the stereo and the heated sets. NADA values aside.
If the year of MFG bothers your ego, remember only the purists can tell your driving an old '04 piece. And most would complement you for it.
roadster with a stick