We use the older Garmin EMap GPS unit. Highly portable, fits in your pocket, mounts to hardware sold by Garmin that can be used in your tow vehicle, sports car, bike or boat. Supporting software is updated about every 18 months. We download the software to our PC and laptop so that we can upload and download to the GPS when we travel. When at home, we download to the PC or upload from the PC to the GPS as well. Have fun shopping around for just the right product to suit your needs.
In dog years, I'm dead!