Trust me just purchase a Garmin with lifetime free updates. Here's a post about our factory installed systems:
So here I am having to use our 3 year old Garmin--which has Free lifetime updates--since our 2014 Navigator or 2014 MKZ can NOT locate an 8 year old established address. I refuse to purchase the Navigator and/or MKZ $150 updates since there's no way to discover IF they have the locations you need. I recommend just purchasing a new Garmin for the same $150 with free updates vs costly updates PER vehicle that last one year.
This has always been why I never ordered a car with factory Navigation. But today this POS is on most new cars. If you're thinking of retro fitting a factory system into an old car, just consider the cost of updates IF they are still available AFTER you install it.