Prepare the grill for cooking.
In small bowl, mix together mayonnaise, Bar-B-Q sauce and spice rub. Cover and refrigerate. In large mixing bowl with paddle attachment, combine ground sirloin, pork and spice rub. Place a sheet of wax paper on a flat surface and empty the meat mixture onto the paper. Form into a rectangle and place another sheet of wax paper on top. Using rolling pin, flatten meat to 1/3 to 1/3 inch. Cut into 8 equal pieces using pizza cutter.
Grill over direct heat for a few minutes on each side, being careful not to overcook.
Toast the buns and assemble sliders by spreading the Spicy Aioli Sauce on each side and then piling on the meat, cheese and veggies.