I have an under seat sub which needs a constant 12v and switch live, as does by Gladden amp which is in the boot. Do I splice into my Connect2 harness? Are there better options? I don't really want to cut into any of the car's wires. Can I go into a spare fuse slot or use a piggy back fuse holder (see below). Where's the best ground? I know there's one in the passenger foot well but anywhere else? Are there any behind the head unit?