I have considered placing a switch in the power line for the radio so that I can eliminate the parasitic draw while dry camping. As I noted in my thread on the electrical system, Roo 19 Electrical
the radio draws 42 mA when off. Now that I added the 3rd battery, I'm not sure it is worth it though.
I noticed that there is an amplified connection for a sub woofer on the system. I doubt it has much power but a small, even cheap, 8" sub would likely make a big difference. I likely won't bother since our primary use is local news and weather reports while camping. Space is also at quite a premium, but a larger trailer would decrease the space issue. Connecting a sub would increase the amplifier load so you may want to insert a switch for the speaker if you do a lot of boondocking and use the radio a lot.
I often use the radio with the outside speakers while out working in the lawn. Just wish it was easier to turn the camper around to point the other direction for when I am in the garden