I have the monster car charger with line out plug. It connects to the dock connector on the iPod. Works great. I can't hear any noise in the system from hooking it up that way and I have really picky ears.
It was $40 and then I bought a decent mini-mini plug to go from the monster adapter to the aux in.
The Most adapter would be nice but I don't feel like spending that much money to hook up the ipod. My only frustration with the current setup is I can't easily change albums/tracks or even skip songs. I have to open up the armrest and look down at the ipod. not good while driving.