I have just completed installing Polk Audio EXII series 5.250 (EX525) woofers and 1" tweeters in the front of the car, Polk 5.250 coax speakers (EX525a) in the rear doors, and Polk dB 6X9 3 way speakers in the rear deck (DB6930). The front speakers were simple enough in the doors and dash. I was not able to use all of the original mounting holes in the door speakers though and I did have to run some wires to the center console for the x-overs to the component speakers. I did have to drill into the plastic to make my own holes. Be sure to use the hardware that comes with the Polks, as they will not rattle out of the plastic after a few days. (I had to learn the hard way) I have the SC-810 with CD-changer. The sound is soo much cleaner than the OEM stuff. However, I will be adding amps in the future as the speakers do require more power and the system is not as loud with the new speakers. The Polks are not nearly as bassy as Boston Acoustic speakers are, but I have found Polks to be much warmer in the mids. and highs. BTW, avoid crutchfield, I have found them to be a bunch of retards. According to them, my 850 turbo does not have front dash speakers, there is no CD changer option for the factory radio, and the rear speakers are not replaceable. Can you say WRONG! They also were wrong about the Bose system in my '93 Accord SE, wrong about the size of the Sony CDX-727 CD changer, and also suggested that I only need 8 ga. wire to feed power to 2 Altec-Lancing ALA-320 4-ch amps (which pull 30A each), 2 MTX Pro 175's (15A each), and cooling fans. Sorry, but they just do not have what it takes to make a good solid install. They did not even know who Altec-Lancing is nor did they know who PPI is. They even said that Jensen makes a decent amp. I guess if you like Geo metro's and Kia Sportages, anything is decent. Anyhow, good luck with the install. It is one of the easiest I have done so far. I spent more time cleaning up tools and throwing away empty speaker boxes than I did actually installing speakers.