I've been typing up some dialogue and came across a few instances where I had 'Jon said' AFTER the line of dialogue (his name isn't Jon, I'm just using a common name here). For instance: "I'm looking to buy a car," Jon said. It seems a tad awkward but I'm not sure if it's grammatically incorrect.
Either way is correct. Some say that "said" + the name of the character is old-fashioned. To see the reason behind this, replace "Jon" with "he." "I'm looking to buy a car," said he. Now compare that to "I'm looking to buy a car," he said.
I may have misunderstood, but I thought that @CMaster asked about the "Jon said" part coming before or after the actual dialogue. If that's the case, it should always come after, I think. Jon said, "I'm looking to buy a car." as dialogue in fiction is non-standard at best.
Jon said can come on either end of the dialogue, the tag's location is interchangeable. In fact, it's likely best to change it up from time to time to give your sentences some variety.
