I tried to make it as clear as possible in that FAQ entry you linked. Guess it wasn't clear enough.

Just place the unit in the car and copy the preset details for #1 into the #2 slot. And/or plug the unit in at home and copy the preset details for #2 into the #1 slot. The leave it.

One thing I don't know...

Version 2.0 has a "copy" feature for EQ presets. But I don't know if this will copy only the details for the current personality, or if it will copy the "home" details when the unit is plugged into the car... Anyone?