Seller has potential easement issue?

[Jeff S.]

I have a seller that thinks they have a potential easement issue. The neighbor (several years ago) and since moved/resold their house, installed an extension on their driveway that runs right next to the property line. I've searched other forums to find advice on this but I'm still not sure where to start. I'm trying to figure out if this is something that needs to be resolved and how to do it with the least amount of expense incurred.

So a few questions:

How far does a structure (or concrete drive) encroach around its premises? Do I contact the city to take a look? A surveyor? I've read multiple suggestions on related threads to contact a real estate attorney, but I don't want to spin the hourly wheel if I can do some of it myself. The add-on was not permitted to the seller's knowledge. I haven't gone to verify that with the city. Also, I'm concerned that I may start off on the wrong foot with the new neighbors if I rent the place out and we just fought a legal battle over the property line. But I also want to make sure I will be getting all the land I'm paying for, free of issues on the front end.