Preheat grill to medium-high heat.
Grill the corn for about 15 minutes, turning occasionally, until charred and cooked through.
In a bowl, mix mayonnaise, sour cream, lime juice, chili powder, and salt to create the sauce.
Once the corn is grilled, generously brush it with the sauce.
Sprinkle crumbled cotija cheese and chopped cilantro over the corn.
Serve immediately with extra lime wedges, if desired.