I've been using Delorme Street Atlas +gps even before the dashboard GPS units show up on the market.
Kept buying new Plus version every few years and do have 2015 SA, what seem to be discontinued and Delorme is part of Garmlin now.
I did like Plus version as in case of flat tire, without internet I was able to find tire shop on my route and call them for availability.
I would contact Garmlin with question what is their policy on computer software.
Finding used 2015 SA is another option.
Even with factory GPS in my vehicles, I like to recheck the route on computer as often programs do have preferences that don't make sense.
Very often I am under impression that software programmers are heavy substance abusers.
