An automated GPS is a worthwhile investment if you are not good with remembering directions or if you are traveling in areas that you aren't familiar with frequently. If you are generally traveling within the same 15 miles, you should probably hold off on buying a gps.
The Garmin Nuvi 255 Automotive GPS System has a really good rating.
You could find the TomTom XL 340S GPS Navigation System for around 140.. with shipping, their may be cheaper but not as functional as the tom-tom.
The best automotive GPS system available would be one that would update automatically on a weekly basis. Roads are constantly changing therefore maps are constantly outdated.
People can purchase GPS systems almost anywhere. There are various online retailers who sell GPS systems. Offline retailers that sell a GPS include Staples, Walmart, Best Buy, HH Gregg, and AutoZone.
There are many different types of automotive GPS systems. But, one that has the best reviews is the tom tom. Here is a link to some of the others. http://reviews.cnet.com/best-gps/
All GPS models should be usable in any vehicle since it depends not upon your transportation but upon its access to a satellite system which determines your position.
Depending on the brand, the price of an automotive GPS unit will vary. The prices of a Garmin have been listed for as little as 120, or as much as 290.
You can compare automotive GPS devices on the internet. Whether it is for quality, price, etc. You can also ask in forums made especially for these kinds of talks over GPS devices or find reviews on the products you are looking for on websites such as amazon.com.
Yes automotive GPS units use ram. Almost any product that has a cpu also has a ram. But because a GPS unit isn't a full blown pc, it won't have a very big ram.
NZ Maps can be purchased online for most GPS devices.
It is becoming more common for vehicles to offer built in automotive gps. Some of the models they are available in are vehocles made by General Motors which feature the onstar program.
Depending where you shop at, you can find a TOMTOM gps system at Sam's club from about $80 online. However, if you are looking for a more topline GPS, they offer a Garmin GPS for up to $200. Also, if you are looking for lower prices you may wish to check out ebay where you can buy used GPS systems for as low as $10 (including shipping).