Mix mayo with garlic powder, wine, and truffle oil if using. Set aside.
In a large skillet cook the bacon over medium heat, until cooked and crisp. Drain on a paper towel, reserving the fat.
In the same skillet sauté mushrooms in the bacon fat for 5 minutes, stirring occasionally. Stir in the leftover turkey meat and cook until warmed through. Mix in bacon pieces.
Savory Blueberry Sauce
Slightly crash the berries with a potato masher or fork. Do not mash them.
Heat the oil in a saucepan over medium-low heat; add the shallots. Cook gently until shallots are translucent. Add the wine and cook until reduced, about 1-2 minutes.
Transfer the berries to the pan and toss to combine with the shallots. Add the vinegar. Simmer the berries for 10 minutes. Add the thyme and season with salt and pepper. Simmer another 10 minutes or until sauce thickens.
If the sauce is too dense, add water. If it's too thin, cook down to desired consistency. Adjust seasoning if necessary.
To serve, wrap the crunchy taco shell with soft tortilla. Place about one tablespoon of mayo mixture on the bottom of each crunchy shell, or until used up. Distribute turkey/mushroom mixture evenly over the mayo. Top with blueberry sauce.