I too agree. If a Gone In 60 Seconds level type thief wants it he/she is going to get it. But I doubt, at least I haven't heard, that those kinds of thieves are targets Kia Souls.
It is the looking to go joyriding, brute force attacking (break window, tear apart steering column), punk thief I want to deter. And so thus finding and utilizing some reasonably priced method - since looking like Kia won't be providing an immobilzer upgrade/update - for (hopefully) causing idiot, unskilled thief to
- not break window and/or
- not tear apart steering column and/or
- not be able to drive car away.
Actually I park inside overnight so my main concerns are for when away from car at a department store or venue, and while parked for work.