I am looking for a way to be able to use my cell phone in my 2005 Dodge Ram Quad Cab hands free. Does anyone know of way to make this happen? I have seen several vendors that offer auxiliary cables that tap into the radio system via the audio system. Any help or recommendation would be greatly appreciated.

You can use a FM transmitter Bluetooth adapter that uses a free frequency on the FM dial to broadcast over the vehicles speakers. Or, you can upgrade your factory system. Check out crutchfield.com. They can set you up with everything you need.

I recommend a new head unit. Even the low end units will have excellent Bluetooth capability for using your phone. I think you will find that a new unit will have other features that are very useful also.
It is easy to install a new head unit in your truck. You can also keep your current radio and put it back it when you sell.
A new head unit will probably cost less than a Bluetooth adapter setup.

If you want it just for music that's one thing, however if you mean hands free calls then you'll need a better head unit.

This little thing right here does hands free. maybe not the best sound quality, but you can find them pretty much everywhere. I have one in my Mustang. Works great.

https://www.walmart.com/ip/Hand-Free...&wl13=&veh=sem

After the stock radio died in my '05, I put a cheap $89.00 Sony head unit in from Best Buy. It has Bluetooth connectivity and hands-free phone via a little microphone that clips to the headliner. I'm happy with it.