There is indeed such a thing as a Manchester Chihuahua. I own one and she looks just like that taco bell dog from years back. She's about the size of a Jack Russel as the poster above related. This information I received from a chihuahua breeder who breeds for sale as pets and show dogs, and at the vets office. I hope this helps.
What? A Chihuahua is a chihuahua. They are either long or smooth coated. There is a Manchester Terrier breed which was a big base for Miniature Pinscher's and look much like a min-pin but larger. There is no Manchester Chihuahua.
When I was younger and lived in California. There were Chihuahua's that were larger in size. Not your little Chihuahua but more like the size of a Jack Russel or a Doxie. My Dad said they were a Manchester. Now if that was a certain kennel or size I am not sure? I just knew they were larger in size but looked just like a Chihuahua. I do have a picture of one. I own one.