1990 300E Becker Replacement

Nice to meet you all...I'm new to this forum. It looks terrific!

My Questions is regarding the replacement of the Becker cassette head unit.

Mine is Toast! So I have a new replacement stereo and I have installed many before. I have been told that the becker system is really in 2 pieces...1 in the dash and 1 in the trunk. I am not sure about this. So I'd like some advice on how to proceed...

Here is what I had planned for tomorrows project...

I was planning on bypassing the colsone fader completly. To do this I was planning on just running all new wires from the speakers to the head unit. The power antenna has me a bit baffled. This cassette unit had about 5 plugs going into it. I think the power antenna wire is blue, but I'm not certain.
I was also told that I needed to run a new antenna wire from the antenna to the head unit. they said something about the factory one going the the trunk mounted portion of the system and then to the becker head unit.

I hope there is some kind soul out there who has been through this and can share insight and tips.

Thanks for the assistance

Steve