I have a few turbo cars, the only time they need tuning is if something changes. For example, if you chnage and intercooler, or up the boost or even bigger throttle body. You should tune each time. If nothing changes, then the computer shouldnt need to be touched.
Yeah, I didn't get the impression that a turbocharged car needs to be tuned now and then...except when you want to wind the boost up or something of that sort...other than that, it's just the standard oil changes, filter changes and stuff.