I just submitted a post, and it's dissapeared
Basically, I was referring to Trigs set-up and mine which does the same, but differently.
Firstly, I have the isolator in the boot (trunk), with the terminals inside the hood (roof) stowage area.
One side is connected to a 10mm bolt (through the fibreglass, NOT touching any metal) with a 6" cable (170amp), which protrudes into the boot area near to the torsion springs. The other goes to the battery positive.
A second cable runs between a second bolt about 12" horizontal from the first one, and the negative side of the battery.
This gives an ideal place to attach jump leads or booster pack if the battery goes flat - much easier than messing under the roof to get to the battery. With this configuration the positive bolt is only positive if the isolator is 'on'.
I also have solar panels, but semi-permanently fitted inside the cars. The ones i got were about a tenner each, and fit nicely on the windsceen at dash level without being too intrusive. When the cars are used more regularly, they simply unplug and go into storage.
One thing to note, if they are to be left in the car when you drive it, they need to be isolated before you start the engine to avoid damage. You can either just unplug it, or do it properly
I fitted a simple switching relay to the fist stage of the ignition switch (that feeds the radio), so that when there is no key in the ignition, the solar panel is connected to the batery (via the wiring loom), when you turn the key the relay operates and disconects the solar panel so no damage is done - all it needs is a 5-pin relay, not a 4-pin, and they are cheap enough on ebay.