Sonic is VILE.  They put one up in my hometown.  One day I was coming back from work and was so hungry, I stopped and got a burger and onion rings.  The onion rings are coated in this thick cake like batter and weren't even crispy.  And the hamburger bun was SWEET.  WTF?  It was so gross and I felt awful after eating half the burger...the onion ring I spat into a napkin.  YUCK.