Grilled Citrus-Mustard Chicken

Oh, this is such a wonderful combination of flavor.  It's sweet, it's tangy, it's perfect!  Enjoy!
-1/2 cup packed brown sugar
-1/3 cup vegetable oil
-1/4 cup spicy brown mustard
-1/4 cup apple cider vinegar
-2 cloves garlic, minced
-1 lemon, juiced
-1 small lime, juiced
-1 1/2 tsp salt
-4 chicken thighs, bone-in, skin-on (or off, if you prefer)
In a large resealable bag, mix the sugar, oil, mustard, vinegar, garlic, the lemon and lime juices, and salt.  Mix very well.  Add the chicken and coat everywhere.  Refrigerate and let it marinate for 8-12 hours, turning the chicken once in a while.
Coat the grill with some cooking spray, then turn it on on low heat.  Shake the marinade off the chicken, and place the thighs on the hot grill.  Cook until done.  Enjoy!