Prepare your grill to medium-high heat.
In a medium bowl, mix together the Mexican crema (or creme friache or sour cream), mayonnaise, 1/2 cup of the cheese, cayenne, lime juice, and salt.
Cook corn in husks on grill for about 12 minutes, until husks have begun to char.
Wearing heat-resistant gloves, remove the corn from the grill, pull back the husks and discard of the silk. Place back on the grill for about 8 minutes, until kernels are browned in spots, turning occasionally.
Remove corn from grill and place on a platter.
Brush with the cream mixture all over the corn while still hot.
Sprinkle all over with salt, a little more cayenne, cilantro and a squeeze of lime.
Serve at once.