Brabus applied its PowerXtra B30 Performance Upgrade to the GLC 300 4Matic, upping output to 296 horsepower and 332 lb-ft of torque (from 255 hp and 295 lb-ft). While not in the same league as Manhart’s 635-hp BMW X3 M creation, bear in mind that the performance upgrade kit is for the M254 inline-four and not the more potent AMG powertrain.
That said, the AMG GLC63 S E Performance and its 671 hp and 752 lb-ft electrified output might be a more viable (and affordable) choice if you’re after numbers on paper. That, of course, means letting go of the exterior Brabus upgrades mentioned above.