You might also want to look at the Audioquest interconnects
as listed in the middle of this page at Audio Advisor. While i know it lists them as "subwoofer interconnects", they could be used for anything that you like. The only reason that they are subwoofer interconnects is that they feed two channels from one connector and are of longer length. If need be, you could always have them cut them to length and re-terminate them. This would get rid of the Y adapter / splitter and minimize two cables, resulting in both a cleaner and clutter free installation. Whether or not you like AQ cables or this specific idea is up to you.
If you don't want to use their cables, you could always incorporate this idea into a cable of your own making. All you would need is a pair of "standard" RCA jacks and one RCA that has an oversized barrel. This would allow you to fit two runs of cable into the oversized barrel, in effect giving you a junction point without the need for a splitter. Sean