if its that frustrating and google.com / ford.com / DIY.com / ecoustics.com / cardomain.com are working out run down to a local Circuit City / Best Buys / Good Guys / HiFi - Buys / Tweeters / Cartoys and ask one of the installers. Generally they answer right there on the spot, no waiting. Then again Schucks / Napa / B. Dalton / Waldens / Barnes and Nobles carry either Haynes or Chilton manuals that have the info between its covers somewhere.