I like the idea. Having location in the thread title would make the classifieds forums easier to browse.
Off-topic:
The lack of location information isn't so much a moderation problem as it is a maintenance problem. Anytime a thread anywhere on the forums gets reported terran or myself are fairly quick to respond, but maintaining good location data is a lot more work.
We would have to read every new post, find the location, and edit the post. When location isn't obvious we would have to ask the author to give us their location so we could edit the topic. If the author fails to respond with location information we would then have to decide if it is really needed for the sale to be offered (do you really need location to buy a shifter boot or fuel injectors?).
Then after all of that, if it is determined that we do need location and we haven't received it in a reasonable time then we would have to delete the thread.
When we first started this system this is exactly what I personally was doing. And it was proven to be counter-productive. Many people posting in the classifieds were first-time, and last-time posters. They register on the forums, making sure not to click the rules sticky, post their message and ask that people email them. Forcing me to delete otherwise good sales.
It's a lot of extra time and it's hard to say when and where being a hardass is beneficial, versus when it is detrimental. So in recent years we've just let the classifieds sections do their thing, letting you guys request location info from lazy posters, and only stepping in when a thread turns into flames or we need to ban the author.