[mouserider]

Ah, the cheaper version of the connector. There is a version that provides full iPod connectivity to the head unit and allows the track advance and back buttons to work, as well as display the song currently being played.

For just extending it, the others right, if it is an RJ-11, then it's an RJ-11, there's nothing special about it unless you're using the word "RJ-11" because it looks like one and really isn't one.

The thing you need to check is that RJ-11s can have up to 6 contacts and most phone extensions you can get in the stores are either just one-pair or two-pairs. You can get 3-pair ones but they are rare and are commonly called 3-line extenders because with 3-pairs, you can have 3 phone lines (POTS).

If you get a standard 3-line version, they will be wired as straight through so it should work unless you go too long and or get lousy quality wires that degrade the signal.