$12,000

It wasn't so long ago that finding a road atlas shoved underneath the passenger seat was standard practice – Hell, we still have one highlighted with our favorite roads in and around our hometown. But with the price of portable sat-nav systems going through the floor, it's simply a matter of time before we see them in cars that cost less than the unit itself.Our friends over at GrandJDM flashed back over two-and-a-half decades and came across this gem from Honda that offered a non-satellite-guided system that's more than imaginative in its execution. You choose a plastic map from the guide book, insert it into the machine, place an "X" on your current position and then a gas gyroscope measures the car's movement, plotting your course. Genius! The only rub was the cost of the system which came in around $2-3k... in 1981... when the Accord it was fitted to cost about$8,000.[Source: GrandJDM]