<<Disclaimer: Verify this information before applying it to your situation.>> Does anyone know if Sonic Drive-In Slushes (Lemon/Lemon berry) are gluten free? They come with a real lemon in them so was hoping nothing artifical. I used to frequent this place on a hot summer day. I doubt anything else on their menu could possibly be gf. I've sent them a letter but no response yet. Thanks, Jill/Texas