Seems like we all know people who have been/are in this situation..
I have a friend who also got a chi. from a parking lot, was promised papers, never got any of them. Their vet has restarted the shots on the puppy. But I told my friend to do her research, and I think when she saw an ad in the paper she just got too excited, saw the puppy and fell in love. When we were trying to get the papers, I called the "breeder" myself, acting interested in a puppy, and to make a long story short we found out this breeder was actually a broker. Their puppy is in a loving home and is spoiled! So far she seems very healthy, and right now that's what's important.