That should be an interesting story, especially after the ride is established and running daily in 2013, 2014, 2020, etc.
I've been on Journey To The Center Of The Earth at DisneySea a few times, and it uses a more advanced version of the Test Track technology, and seems to work well there.
I have a hunch they've gotten the major bugs worked out of the Test Track technology by now for the later versions of the ride system. But I also have a hunch it's going to be the multiple track switches along the ride track and changes from a single-lane dark ride to a dual-lane racing ride outdoors that will cause the most headaches for WDI and Disneyland's maintenance department.
Following this ride track layout of Radiator Springs Racers, and it's those track switches from outdoor to indoor and single-track to dual-track that seem to throw a lot of brand new problems the way of the engineers and the maintenance guys.
http://i49.tinypic.com/5tz2ar.jpg
But, at least SoCal gets only a handful of rainy days per year, so they won't have to worry about the rain and lightning that shut Test Track with regularity year round, and can also wreak havoc in Tokyo's rainy weather for the outdoor portions of Journey To The Center Of The Earth.
For those unfamiliar with that image above (I just realized that may be a new image for many East Coasters here), the
blue lines are the ride track and the
red lines are the queue and exit paths. The
green shaded areas are the entirely indoor dark-ride sections of the ride. The
grey shaded area is vehicle storage and maintenance area. The
tan shaded areas are rockwork and semi-indoor areas. And the white areas are completely outdoors.
The numbers correspond with the following;
1 = Unload Area, with off-line wheelchair boarding zone
2 = Loading Area
3 = Track goes over bridge over waterfall as vehicles climb rockwork facade
4 = Car Prep Room 1 for race sequence
5 = Car Prep Room 2 for race sequence
6 = Bunny Hills on fast race segment
7 = Super-banked turn on fast race segment