I know there's a module you can buy that plugs into the harness for the CD changer or XM radio (e.g. you lose either CD or XM) but that adds bluetooth functionality. I personally would rather USB audio and I have not found any solutions for the OEM USB audio as of yet. https://www.amazon.com/USA-BT45-HON3-Bluetooth-Select-2003-2014/dp/B00NMXMUW8
I'm the same way as you, though. I hate the look of aftermarket stereos and would much rather have something as factory as possible.
if you have radio with XM, you can always use this - it adds good BT and another AUX port
https://www.amazon.com/USA-BT45-HON3-Bluetooth-Select-2003-2014/dp/B00NMXMUW8
Even though I did it, I'm not sure I did it the right way lol when I get home I'll give a few pointers so you can have a better start than me. I broke a few plastic tabs and that big panel doesn't sit exactly perfect anymore but unless you are looking for it you don't notice.
https://www.amazon.com/dp/B00NMXMUW8/ref=cm_sw_r_cp_apa_fabc_I.r1Fb33D0SG9?_encoding=UTF8&psc=1
both of these links are for the same product but I've heard you don't get returns for the one you buy on Amazon. So it might be best to get it from crutchfield, the people that make it.
You should also get a set of plastic trim removal tools. I think you can get a pretty cheap set from harbor freight. That way you don't damage any plastics
This is the one you want to have.
USA SPEC BT45-HON3 Bluetooth Phone, Music & AUX Input Kit for Select 2003-2014 Honda & Acura Models https://www.amazon.com/dp/B00NMXMUW8/ref=cm_sw_r_cp_api_fabc_pCsQFbR2FNHMT?_encoding=UTF8&psc=1
It plugs into the Sirius/XM port in the back of the radio and gives you Bluetooth integration that is factory quality. For wired aux input, I removed one 12v in the front and added this in its place:
USB Mount Cable - Rerii 1M 3 Feet USB and 3.5mm Aux Extention Mount, Flush, Dash, Panel Mount Cable for Car, Boat, Motorcycle https://www.amazon.com/dp/B00VAIEAUM/ref=cm_sw_r_cp_api_fabc_DEsQFbART13PP?_encoding=UTF8&psc=1
The install looks like the truck came that way and I have no wires outside of the dash. It’s all tucked away neatly.
Yeah, u/snaveleinad get one of these and be done with it. Here's the Amazon link:
https://www.amazon.com/gp/product/B00NMXMUW8/ref=ask_ql_qh_dp_hza
Here's my post about it from a year ago. I commented at the bottom about how it took all of 10 minutes to open my trunk, pull away the lining on the right side, and connect the Bluetooth receiver to the XM receiver (it comes with instructions). Was the best money I ever spent on that car and made streaming music & nav a breeze. Had a vent phone holder thing that held my phone above the OEM radio.
Does your Accord have an option for XM radio? I went the bluetooth route with a transmitter that plugged into the XM receiver in my 2006 TL's trunk (since replaced the car) and it was super easy to install, and worked flawlessly.
https://www.amazon.com/gp/product/B00NMXMUW8/ref=ask_ql_qh_dp_hza
My post asking r/acura about it, I have an update comment at the bottom - https://old.reddit.com/r/Acura/comments/6zuotg/anyone_using_the_usa_spec_bt45hon3_in_their_3g_tl/