Where do you guys attach power wires for cruise control, efi, stereo amps, etc... and keep the battery clean looking?
When I had to add a main power wire to a side post battery, I would use these style adaptors:
Or I would use this style that are like a bolt threaded into another bolt:
On the above the shorter male threaded adaptor is probably designed for a single molded cable end while the longer ones reminds me of the setups for dual batteries and dual connections like in diesel applications.
Off of a side post adaptor, you can then run a wire to a fuse or circuit breaker and then to the device you are adding or one could run a short proper sized and routed wire to a fused distribution block to have it set up for something like a 20A draw for an audio amplifier, a 5A fuse for a cruise control, a 30A for a cooling fan relay, and so on.
Be aware though that if you start pulling a lot of excessive power off of the battery positive post, then at a point, the battery negative to chassis connection needs to be upgraded. Remember what you pull out also has to get back.
On a side post setup, do not try and "Cheap Out" by adding a ring terminal between the battery terminal face and the face of the cable end. The factory bolt may not be able to go in far enough to where one could pull threads out of the battery post. How the battery terminals and cable ends are designed is they are more sealed reducing the chances of corrosion and the added thickness of a ring terminal in the wrong spot now allows more of an exposed/open connection.