This will I am sure be old hat to the majority of people but for ages now I've been using a Sat Nav in the car to get from place to place and in most cases that has been absolutely fine.
Recently I have on several occasions had the need to get to particular places or "points on the earth" where there is no readily available post code, address or anything close by. An example of this was locating suitable support locations when down at the Mersey Roads 24 Hour TT.
What I've been doing is having a look at likely spots on Google Maps and then zooming in and checking places out using the satellite view and Google Street view. What I've then done is identify my target spot and get the latitude and longitude of the spot, which can be in the middle of nowhere of course. Having done that I key that data into the Sat Nav and it takes me faultlessly to the lay-by, bend, or whatever.
As I said, this is probably old hat to most folks but I've not used the car Sat Nav in this way before and it works a treat :-) Au revoir post codes, bonjour Monsieur Latitude et Madame Longitude :-)