At least 8 hours before serving, preferably overnight, lightly spray a rectangular glass baking dish with cooking spray. Place the pork loin in the dish. Mix the next 6 ingredients and pour them over the pork loin. Cover the dish and place in the refrigerator, occasionally rolling the pork loin to distribute marinade.
Approximately 30 minutes before baking, remove the cover and rub the pork loin with the lemon-pepper seasoning. Allow the dish and pork loin to stand at room temperature, uncovered. Mix the ingredients for the Lemon-Garlic Aioli as follows: In a medium bowl, place the mayonnaise. Add the Dijon mustard and garlic, stirring. Slowly dribble the lemon juice in, stirring while adding. Add the thyme, stir. Add salt and pepper to taste. (You may wish to re-plate into a serving dish now). Cover and refrigerate Lemon-Garlic Aioli until serving.
Preheat oven to 400°F. Place a meat thermometer into thickest portion of roast. Place uncovered roast in baking dish into oven. Roast for 50-60 minutes or until internal temperature is 165°. Remove from oven and allow to stand for 5-10 minutes before slicing for serving. Pass sliced roast with Lemon-Garlic Aioli.