More cilantro, chili powder and lime wedges to garnish
Preheat grill to about 400°F. Place shucked corn on grates and grill until nicely browned but still tender, about 3 minutes per "side," 10-ish minutes total. Place on a serving platter to cool slightly.
In a small bowl, stir together the mayonnaise, crema or sour cream, chili powder, garlic, lime juice and zest, cilantro and salt.
Spread sauce over corn with a spoon. Sprinkle with Cotija and with extra cilantro and chili powder. Garnish with lime wedges and serve warm.