Recommend me a car navigation system (GPS)

I’m looking to upgrade my car navigation system (GPS) and would like some recommendations if you don’t mind. I currently have a Magellan Roadmate 1412 that’s several years old and doesn’t have a particular feature that I’m wanting.

What I’m looking for is a car GPS system that will allow me to input a destination or POI using latitude and longitude coordinates rather than street address. I spend as much of my leisure time as possible hiking and fishing in some of the nearby state and national parks and forests and would like to be able to navigate to trail heads, stream crossings, and such like without having to try to read my DeLorme road atlas or topo map and drive at the same time. I do have a hand-held GPS unit that I use for trail mapping and off road use, but it doesn’t do turn-by-turn driving instructions for getting to my targeted starting point. Anybody know of a car system that would do that?