The NG4 system was launched in mid 2009. The unit itself is made by harman becker (maybe you have heard of them? they are also harmon kardon, jbl, infinity, mark levinson and others) .They provide oem sat nav systems to many manufacturers such as merc,lexus,toyota etc (which by all accounts are exactly the same as the operation in the pug versions) and the mapping is by navtec.
Why does the system only takes a 5 digit input.....nearest I ever got to an answer was from a satnav manufacturer and that is that the UK is a pain in the ass as it uses an alpha numeric system and should use a 5 digit number system like 99% of the rest of the world does hence we get a 5 digit input as we are the minority market. I was driving a 3 year old Audi A8 last week, 60k car when new, same 5 digit input as the pug.....Aston Martin have only recently started full postcode input on their sat nav system on a car that can cost 4-5 times the price of a well specced RCZ.
While tom toms have full post code most wont be able to naviagte you around the whole of northern europe with voice recognition and command, play films on dvds, play mp3s from an Sd card or memory stick, allow you to rip something like 100+ cd's into the hard drive creating your own in car "jukebox" , have a choice of blue tooth or a fully integrated internal phone, display the front and rear parking sensor warnings on screen with coloured distance bandings, look cool on your dash....
The NG4 will navigate down to the actual door number of an address if you ask it to.
Also setting a "HOME" address in a built in car sat nav isn't a great idea, if some scumbag nicks your keys while your out they get in your car which then navigates them to your house....BBC tv did exactly this to someone on the real hustle programme.
regards
Marcus