If you want drop-in's, the Rainbow IQ120's are about as easy as it will get - remove/unplug old speakers, plug in and refit new speakers. The sound is clear and crisp, although they are a little bright at first (I think everything will be a little bright compared to stock). You won't get a whole lot of midrange out of them, however with a sub there should be enough low end oomph that the little dip in frequency response between where the coax's drop off and the sub picks up shouldn't be too bad.