I have GPS in my '03 Boxster S and am amazed at its accuracy....but then I never had one before.
When traveling to the UK it found the most remote places and directed us safely to hotels/restaurants in towns we had never been to to before. All rather enjoyable and you can even chose different the directions being given in different languages (Finnish, Italian, Swedish, Dutch, etc) as well as male/female.
Admittedly it is a rather expensive option but being a gadget-fanatic, I just couln't resist!
