Mobile HF antennas and tuning

At present for mobile HF im using Hamstick type  single band antennas. The problem with these is they are rather big for a little car, and its quite a faf to change them to go to another band, especially if im just listening about, where I might be outside the amateur bands.

So, at the risk of reduced efficiency on lower bands, im considering installing my LDG RT-11 remote auto ATU alongside the FT-857D, which hopefully will give me some improved frequency agility, and particularly, allow me to use a shorter antenna for general utility listening.

The RT-11 is capable of fully automatic operation, retuning itself on any frequency change greater than 10kHz. But the manual states that the control line for this should be grounded momentarily on powering up, it doesnt say if it can be left grounded. It would be quite awkward to add yet another remote control cable between the radio installation and the control position at the drivers seat, so I need to find out if it will work as needed.

Unfortunately im not in a  position to test the theory for a few days!

I also need to haul out any junk I wish to take to sell at this years Finningly rally on the 16th!