Not enough info. Works only for stereos with AUX option
357786
Bought this thinking I could plug into my car stereo but in never mentioned that it only works with an AUX option. Had to completely destroy the box to get it out so I can't even return anymore. Probably works well if you know what you are buying.
3316455
My car is an older model with no aux cord, so I thought that this would be the perfect solution for that. Unfortunately, I found that my favorite radio station received a lot of static if I synced the device to a lower FM frequency. Alternatively, when I synced the device to a higher FM frequency, the sound coming from my phone was filled with static and not very clear. The radio static would only clear if I totally pulled the device out of the cigarette lighter port, which is not easy to do on my vehicle. I suppose this would be fixed with an on/off button, but it's disappointing that this glitch can only be fixed by purchasing the plus version.
5792
I had gone through several male to male audio cables finding that none of them supported stereo.  You need those three bands in the plugs!  I use cables like this to plug into my iDeck and similar devices so I can listen to my MP3 music over my car stereo.  I also plug one into my headphone jack on my laptop and the other into one of my stereo input jacks and am then able to play from laptop to stereo.  This is great when the devices you're using are not airplay or Bluetooth compatible.
2613401
I bought this to replace a previous Aux input interface that I had installed about 7 years ago, that had lost a channel  in my 2006 Ridgeline. Installation was simple, just pull the face of the Dash off, 5 screws that hold in the radio, and the rest is plug and play.  The bad news is that the volume that came through the Aux input was about half of the Regular radio. With the volume turned all the way up to # 40 ,It was about as loud as my CD/Radio at #16 .  I tried playing with the dip switches to make sure the input was correct, But it made no difference.  I pulled apart my 7 year old broken one that I had removed, soldered  the bad input RCA plug , and re-installed my old unit , and it works fine, Just as loud as my regular radio !  So the New PAC unit will sit unused....
1795930
I have a 2008 Lexus IS350 which has Bluetooth phone function but no A2DP.  I'm looking for a wireless alternative to play music via the AUX port.  Physically, this fit perfectly in the center console where the power outlet and AUX inlet is located.  The device reliably auto-pairs as soon as I turn on the stereo - no need to turn on any power switch.  Bass is noticeably underpowered and the audio a bit diluted, but I'm willing to accept this compromise.  Deal breaker: every 60 seconds, the music stutters, like an old record skipping.  Renders the device totally useless - a waste of $60 bucks.

Update 11.21.2013:  Switched music app to PowerAmp (after trying other apps) and installed PAC ground loop isolator.  Music now stutters about 1-2 times an hour - more when driving at night, which I assume is related to noise created by the headlight circuit.  Auto-pairing was great when new, but is becoming less reliable with time.  Sound quality remains barely passable.  The New Potato TuneLink would seem to solve all these problems (internal noise filter and superior software), but it simply won't fit in the IS350.
2550835
Connected system with existing wired speakers.  Would work for a few songs, then the system would automatically lower the volume of the wired speakers so effectively, they were off .  Do not buy if you plan to integrate this with wired speakers.
3514122
This cable DID NOT work with my Zen Vision MP3 player as it has one more band on the plug. My earphone jack has the tip and two bands, these had the tip and three bands. Once plugged into my car (2009 Altima) the Zen player went weird and out of control. Guess I need to find one that has the same looking plug as my earphones. Even though the description says "MOST USED FOR: Ideal for connecting iPods, iPhones or Media Players to car stereos or speakers"  . . . . . this is not correct in my case. Maybe iPhones & iPods can use this extra connection on the plug, but the Zen can't. Disappointing.
2144533
Doesn't work with stock subwoofer,steering wheel controls don't work, sync doesn't work factory sub and aux don't work
2970925
I use a 1/8" to 1/8" from my laptop to this FM transmitter, and I only get the right side stereo out. Missing the left. I attempting to bridge the input but I dunno if there is another way to get this broadtcast in stereo.  O well.  Well eventually the Mic input failed. It has been a piece of *** since I bought it. Trying a different brand now.
3791696
I just bought this but am in the process of returning it because it has no output or headphone jack. I saw the MP3 capability as a way to tie into my regular stereo equipment so that I could leave a single CD in for a party and walk away. Obviously you need some sort of output jack for that.
I tried to figure out from the online info whether or not this had such a jack, and finally decided that nobody would be dumb enough to make a boombox at this price point without a headphone jack. Wrong answer.
My 5 minute test suggests the sound is decent enough though. If you don't need to tie this into any other system, it is a good buy.
4556073
The base/part with the logo below the jack is too big to fit into most bluetooth-accessible headphones, so they are pretty much useless for headphones. However, if your car as an aux accessible plug-in, this would be great.
2230308
Before I bought this, you told me that it would pair in TX mode with my car audio. It did not. You wasted my time. I returned it, but it is very annoying that I can't get an honest answer from a company about the capability of their product.
2957460
I bought this to work with my Ipod shuffle and the advertisement said it would work will all kinds on auxilary but that is not true. This will not work with the shuffle.
4707253
No RCA out!  How would one hook it up to a stereo?  Answer: you can't.  Completely useless!
1721587
Make sure your existing stereo is a bose system.. otherwise it will not fit. This only works is the vehicle has a built-in amplifier.
2339055
Bought as a gift for use with an MP3 player. Aux port didn't work so worthless for intended purposes.
912380
I bought this with the intention of plugging my ipod into the usb port. WRONG. Apparently you have to plug it into the AUX port? Who makes a receiver that isn't compatible with the biggest mp3 player in the world? I contacted Dual customer support and they have yet to respond. The sound quality is better on low than when you turn it up because it gets distorted past 10. Have yet to try the bluetooth which should be arriving today but I am severely disappointed because I only bought it for the Ipod port.