Permanent power to hidden auxiliary battery to GPS tracker hidden really really well
Basically you need to pull the dash out and hide it deep in there, or underneath the car, or in the boot to be "super sneaky" to do it OCD style, but in saying that, there are only so many places you can hid them, but the longer it takes to find the tracker the longer you have of finding the car
Sometimes with dumb thieves a simple install will work, so just up under the dash, or in the boot, or under the car is good enough to find the car after a joy ride or in their back yard, but then a simple "quality" aftermarket alarm will usually defeat the average thieves
But, good "professional" thieves know what to look for and how to defeat it, and if it is worth the time and effort to defeat the GPS/alarm before it goes to the final location to be stripped/rebirthed, you'll never see it again
Typically there are a few ways that they get your car
Scum factor: random thieves, joy rides
Opportunistic: thieves have been given a list of requested parts, rims, straight panels, spec interiors, or, know they can easy sell the bits you have bolted to your car
The targeted: known cars, if you post stuff about your car thieves will be taking notes, if it meets their "customers" requirements, or what is demanding big dollars on Gumtree or Ebay they will try and track the car down and grab it in any way possible, break in, home invasion, advertised meets, you name it
There's also the rebirthing/ repairable writeoff business that has aways made coin
I've even heard of them placing their own GPS, and/or follow and track the car back to the location of high end targeted cars
Most opportunistic and targeted stolen cars are stripped of parts within an hour or so of being stolen,with the shell either being dumped, burnt or "feed to the pigs" (scappers)
The best way to protect your car is to keep its location hidden and/or don't post up build threads about your location, $5k rims and tyres, twin turbo/supercharged/fully built bolt on builds, HSV this, and Walkinshaw that, stored in secured and alarmed garages and locked behind bollards, with a good a alarm and GPS
Always remember, "midnight spares" is a business that has been going on for years, supported by all types of criminals and businesses (read:wreckers)
Blocking the crooks knowledge and access is always step 1 to security
My old girl live behind gates, behind other gates, that are patrolled by the AFP, it also has multipe levels of anti-theft and tracking devices when it is out and about, in saying that it also has comprehensive insured
I've had 2 cars stolen before, it sucks balls ,and you do what you can to not have it happen again