Car Stereos: wiring headphones, sony car stereo, sony head unit

Question
Please help. I would like to know the correct way to wire a headphone jack/headphones to a Sony car stereo being mounted on my year old lawn tractor. I have been using noise canceling headphones and an mp3 player but the players's volume level will not compete with the mower. Also if wiring a jack to the speaker wires do I need to use resistors so it will not fry the stereo or headphones? The car stereo has an aux. input for the mp3 and I would really like to use the noise canceling headphones with this unit.
Any assistance you can give on this project is greatly appreciated.

Answer
Hi Rudy,

Sorry about the delay in answering your question.  

Your best bet is to look for a low-level output on the back of the head unit.  This output would be in the form of RCA jacks.  Nearly all after-market head units have this type of output.  If they're present, then all you need is a Y-adapter cable to convert the headphone plug to a pair of stereo RCA plugs.  Here's an example:

http://www.cablestogo.com/product.asp?cat_id=2009&sku=40424

If the RCA output isn't available on your Sony head unit, or if you find that the output level is still too low, you can try using a line output converter.  This is a device that will convert head unit's speaker-level outputs to low-level RCA outputs.  It can be found at just about any store that sells car audio accessories.

Hope this helps!

Brian