Strange. It sounds like you have the BA6 system and the sub is supposed to be in the rear deck shelf and the amp should be under the dash like all the systems.I don't have a sub. The unit says amplifier right on it.
someone else would have to verify, but I'm not sure whether you havei bought it used and all i was told was factory deck with 6 speakers
i looked at that spot and i see nothing
so now im off to get a cheap harness until my new deck arrives
Good thread and it answers a lot of questions! There's another link within it explaining the how to for getting at the amp as well - http://www.300cforums.com/forums/faq-archives/9359-how-access-factory-amplifier.html.Take a look here and see if this helps you....some folks went without a harness, but wound up not being able to shut the radio off. That is because there is no switched power at the radio. However, you can find such a wire (example fuse 18 in the switched position which would let you use the cigarette lighter feed). In that case you can use the FAQ for the wiring diagram, and make your connections that way.
As for how I would do it......I'd buy the correct harness from the
start to be safe.