That ticking sound isn't to indicate that they are on, thats the sound of the flasher unit turning on and off.
Most cars it will be audible in the passenger cabin because the flasher box, which isn't a standard relay and may be a round unit in some cars, is in the interior fuse panel.
The flasher unit is also based on the resistance in the turn signal system, so if a bulb goes out it will flash faster, which is a perfect indication that a bulb is out.
If a GTR has turn signals or even just 4-ways it's garanteed it will have a flasher unit, and thus it will have the ticking sound. The unit is so small it's not even a consideration for weight savings either.