intercooler on 2015 jetta

bought a buy-back 2015 jetta. Doesn't have a conventional intercooler, just a big aluminum box on the front of the engine. anybody know how this works.

Yes, it has an intercooler. It is an air-to-water-to-air type.

The charge air cooling is done via a heat exchange in the intake manifold with coolant, then that coolant carries the heat to an additional radiator up front, where it is released into the air.

There is an additional electric coolant pump tasked with the purpose of circulating this coolant path through the intercooler and additional radiator.

That explains the sound of a motor running sometimes when I park, also the radiator fans sometime run for a few minutes after shutdown. Thanks for the info.

The fans run during and after a regen.