Satnavs to put you on the right track

BUILT-IN cost a lot more, but offer extra features.

On the BMW 3 Series, satnav comes with a full control set-up.

IN an infamous convertible launch in Sweden a few years ago, the test fleet ended up in a field.

Saab had so much faith in its satellite navigation it relied on the system, instead of the usual printed route instructions, to guide the motoring journalists.

Saab was one of the last premium makers to build in satnav to its cars, which by the middle of the noughties was common on premium imports.

Like other recent technology, such as Bluetooth phone connectivity and hard drives for music, it has trickled down quickly to volume brands.

Now, satnav is available on popular small cars, such as the Mazda 3, if you pay for one of the premium versions that start at $27,690.

Last year, when Ford began fitting integrated satnav on the Falcon, it included real-time traffic information feeds by Suna.

That's advanced stuff, which in this market many of the European carmakers are unable to offer.

On a car like a BMW 3 Series, specifying the full satnav involves ordering the entire control set-up that goes with it, which accesses all the car's functions via a screen and rotary pointer.

While standard on expensive models, it's $2900 on a 320i.

The Falcon system looks a relative bargain at $2290.

However, aftermarket devices from most of the big brands, including Mio, Garmin, Navman and TomTom, cost a fraction of the price of optioning satnav into a new car.

They start at about $100, and even a top-of-the-line Navman MY500XT, with a host of features, costs less than a quarter of the Falcon price, at $549.

A key advantage for integrated systems is precisely that -- their integration with all the sensors and chips that monitor everything on modern vehicles.

They can interact directly with data about fuel consumption and servicing needs, and may even keep working in tunnels.

Aftermarket systems, which rely solely on GPS, start throwing up unhelpful options when they lose the signal.

Aftermarket devices are necessarily more vulnerable to casual theft, and finding a suitable place to locate one, especially those with large screens such as the Navman MY500T, can be a problem in some cars.

A smaller Garmin Nuvi 1390T, for the same price, is likely to be easier to position.

Both, of course, require power most of the time, so they must trail a wire to one of the vehicle's power outlets. That means sacrificing power for something else, and wires can be a nuisance.

If it doesn't hinder vision, an aftermarket unit set low on the windscreen, just above the dash, is in an ideal position for eye contact while the driver is still watching the road. This is where heads-up displays, such as the ones available in high-end BMWs, project their information.

However, few carmakers put satnav screens that high and many are set too low, in the centre console.

Portability is an advantage if you're constantly swapping vehicles or use satnav for purposes other than driving. I, for one, can easily get lost at walking pace.

When you're in some forsaken part of a metropolis and don't know which way is up, being able to simply press Home is one of the joys of our information age. In a car, it means no more balancing a directory on your knees.

The aftermarket often has the edge here, with simple, intuitive logic to their controls and rapid reprogramming. Car systems, by comparison, can be unfathomably complex and sluggish.

BMW's iDrive -- until overhauled recently -- was rightly notorious for being confusing, with all functions, including satnav, a nightmare to negotiate.

However, the other carmakers are in no position to throw stones. Without a manual, they can leave you stumped. I've sworn at all of them, without exception, when trying to reprogram on the run.

The aftermarket makers can also respond more quickly with innovations, such as photo-like representations of slip-roads and junctions. These can be crucial for avoiding ambiguity in situations where a spoken command or symbolic arrows are not enough.

All the main brands offer the Suna system, and include features such as spoken place names and camera alerts, which are rarities on integrated systems. They're still getting the hang of 3D maps.

A sign of the power of the aftermarket is that carmakers have begun offering portable devices of their own. However, I've yet to try a system that was faultless in its mapping, commands or operating logic. Crazy directions, such as asking for impossible U-turns, are not unique to either.

It's not unusual to test-drive a new car on a road that simply doesn't exist in its mapping, even though it has been operational for years. Or it might take you down a road long since overgrown.

Perhaps that was why all the motoring press ended up in the long grass on that Saab event. Or maybe it was something more serious, because now the whole company seems to be heading towards a dead end.