I installed one of the OE Hella ones today. Just loose cables, tucked in on the side of the battery and under the spare wheel. Seems like it will work just fine.

But, I now actually think the best solution for me may have been to use one of those quick disconnect switches like this:
Battery Disconnect Switch

It looks like I would be able to reach through the wheel and turn the knob to enable/disable it. I have one of these on my old 911, which I don't drive so much, to keep the battery from discharging too much, and it has worked very well for many years now.

Either way, I'm glad I no longer have to remove the spare tire every time I work on the car.