Becker iPod cable
I agree... $50 for a "cable" sounded like a lot to me, but I couldn't get the pin-out diagrams for the 5-pin din plug for the rear, so bit the bullet. After I received the purchase, I didn't feel so bad... the cable is nicely molded, and, on the other end, the 1/4" mini-jack is pre-mounted in a nice little compact housing, suitable for mounting unobstrusively under the dash (I decided to just drop mine in the glove box,running the wire from behind. It also included the separate male-to-male 1/4" cable to actually connect the Becker jack to your iPod...
all in all, I figure I would have wound up spending a good $30 at Radio Shack for individual parts, if I could find them, and then futz around for an hour or more getting it all together... then the $50 seemed like a pretty reasonable deal.
I've been astounded at both the clarity, fidelity, and volume of sound the Becker can output from the ipod source. My system has modern but low-power consumption speakers, but no external booster amps...With the cabin noise level, I wouldn't be able to discern stereo separation anyway!