Stereo change confusion

[Kainen]

Hi i have a 2005 celica gts with the jbl upgraded stereo, when i pulled the stereo out to put an aftermarket one in i found the joy of the regular harness not fitting but have finally found another harness that will fit but the next thing to figure out it this... above where the antenna plugs in is another similar but smaller hole with a cable that looks like the one from the antenna plugged into it but smaller as well the aftermarket stereo does not have the two holes for antennas to plug in... what is this second smaller plug in that looks like the antenna plug in and what do i do with it installing the aftermarket deck?

[woofer212]

factory satellite radio antenna plug maby?

[Kainen]

ok if anyone else was wondering this too, after extensive websurfing the smaller skinnier antenna plug that goes into the second hole is for the "fm diversity" and whatnot for better fm tuning. and most people just leave this one unplugged after installing aftermarket decks. i saw a few that posted that they were going to get a y adapter and another adapter to make the smaller one fit and plug both of them in but they never posted follow up results so no idea if doing that makes any difference.