It's probably overkill given the setup I'll be using, but I'd like to retain as much stock function as possible. There shouldn't be a scenario where the Volvo efan couldn't handle the temps, so the aux fan is just a simple added booster to help keep the system cooled efficiently. Since it's mounted directly in front of the condenser, it should do a better job of keeping it cooled than an efan alone when it's running.
