Many people will say NOT to go this route, BUT I ahve been using one of these FM transmitters for several years now and find it to be convenient AND of more then acceptable sound quality. It is the Transpod Classic, made by DLO. It plugs into the cig lighter, to the right of my steering wheel, and an exceptionally easy to read and use height. This particular FM transmitter was reviewed by several electronix blogs and got solid reviews, unlike others which do not work nearly as well. It is both a cradle and a charger and a player for iPods. Here is a link for one that is an open box return with full warranty --
Digital Lifestyle Outfitters 009-3033 DLO TransDock Classic - Digital player car holder / FM transmitter / charger - iPod -- though I have never done biz with this site. (It is a hellava deal, though, as I payed close to $100 for each of ours and this one is listed at $20).
Again, my wife and I have used 2 of these for combined 3 years of use and have had NO issues.
Just my thoughts on a possible cableless solution that is convenient and still sounds great, IMHO.
If you want me to, I could possibly post a pic of how it looks in my truck.
PS--I am only spaeking to the DLO Transpod Classic iPod tuner, and not there "micro" or others. It is possible that the newest DLO Transpod 3. 0, is as good as the Classic, but it does not have sides on the cradle, which I don't like for our bouncy trucks, but it might work just fine.