I did some investigations on the current market, there are a few choices if your car does not come with a navigator
1. In-car portable navigator
(a) standalone
(b) relatively expensive
(c) hopefully the map is more accurate and friendly (voice with street name and highway exit number, but I doubt it)
Currently available equipments in the market
* Garmin StreetPilot (about USD 2,620)
* TomTom GO Portable Car Navigator (about USD $880)
* Magellan Roadmate 700 (about USD 1,000)
* Navman iCN 630 (about USD 550)
2. Hand-held Integrated Navigator (PocketPC & Navigator)
* Navman PiN (USD 450) - Windows Mobile 2003
* Garmin iQue 360 (USD 610) - PalmOS (compactibility is a big concern)
3. PocketPC with integrated bluetooth & wifi
* HP 2215 integrated bluetooth, no wifi, 300MHz, 64M RAM, windows mobile 2003 (USD 300)
* HP 4155 integrated bluetooth and wifi, 400MHz, 64M RAM, windows mobile 2003 (USD 400)
* Dell Axim X30 624MHz, 64M RAM, Integrated bluetooth & wifi, windows mobile 2003
You need to buy a bluetooth GPS and navigation software, about USD 150.
Summary:
Option 1: more accurate (hopefully), expensive, only navigation system, portable from car to car
Option 2: integrated GPS and navigation software & map included, plus PocketPC, but need to add SDIO-wifi for network communication
Option 3: Essentially a PocketPC but with integrated bothetooth make it ideal connect to bluetooth-based GPS receiver. Great compatibility inherited from windows mobile 2003 so that there are quite a few commercial navigation software & maps in the market. For example, Microsoft streets & trips 2005 (acceptable accuracy, not meet professional level), Navman SmartST v2.
----
I tried Microsoft streets & trips 2005 with my laptop, it is unacceptable. Only good when you are lost and stop to check with the map. Then you know where you are exactly. Not recommend laptop + GPS receiver for instruction while driving.
Personally, strongly recommend
Option 2 - Navman PiN
Option 3 - Hp 4155 + GPS + navigation software
I don't want a navigation system only, I would like a PocketPC as well. Both options can do the similar jobs, but the option 3 has a wireless access (802.1b). By the way, you are able to replace the navigation software for Navman PiN as it is powered by windows mobile 2003. But SmartST is better than MS streets & trips 2005.
Make your smart choice.