unlock honda radio

sometimes they put the code on a sticker inside of the glove box or on one of the sides of the glovebox.  Look in that general area and you might find something.  Also I don't know if you have any of the original paperwork but I've seen on the initial inspection ticket thing  they sometimes will put it under the section called "key code".

If you can't find it either of those ways then you have to pull the thing out and give honda the serial number that's written on the top of the unit; and they will look it up for you.  It is possible that they might have the VIN linked to the radio's serial number in their computers but I doubt it.  Worth a try though.