Place zucchini and summer squash in large plastic baggie or tupperware.
To squash, add olive oil, cumin, chili powder, salt, lime juice, and garlic. Stir well to combine.
Let sit for at least 30 minutes, up to overnight.
Meanwhile, you can make the Mexican Street Corn Salsa (below)
Preheat grill to medium-high heat.
Place zucchini in mesh grill pan or in foil.
Place onto grill and cook until squash is tender, about 10 minutes, and it has nice grill marks. (Note: it probably won't have grill marks if you make it in foil)
Serve in tortillas, topped with Mexican Street Corn Salsa.
To make Mexican Street Corn Salsa:
Bring large pot of water to boil.
Add corn and boil for 10 minutes.
Once cool, cut kernels from cob. Alternately, you can use frozen corn and cook in microwave.
Combine corn with mayo, yogurt, chili powder, lime juice, jalapeno, cilantro, and cheese.
Stir to combine.
Top zucchini tacos with street corn, then sprinkle with chili powder.
Serve and enjoy!