If you buy a high-end Mercedes-Benz with the included navigation system, you won't have to figure out how to work the controls: Just press a help button and Mercedes will download the destination for you. This feature, called Destination Download, comes on 2007 S-Class and CL-Class Mercedes-Benzes.

Here's how it works. The flagships of the Mercedes-Benz sedan lines, the S-Class and CL-Class, include navigation systems standard along with TeleAid, the Mercedes-Benz telematics, assistance, stolen car recovery, and information service. Press a button on the overhead console for a connection to an operator (via the car's built-in cell phone), and tell the operator where you want to go. The destination information is sent back to the car via the cellular data link, and your car is ready to start following the route. For anyone who has trouble making a navigation system work, Destination Download could be a viable solution.

Destination Download is much like the General Motors OnStar Turn-By-Turn service but also has a big difference. It requires you to have an installed navigation system with map information on a DVD disc (or hard disk) in the car, whereas Turn-By-Turn downloads the map information, called a route corridor (meaning the road you're supposed to take and some adjacent roads in case you go a little off course), to a simple storage module and a one- or tw0-line display. However, if you opt for GM's generally well-regarded (on recent models) in-dash navigation systems, there's currently no way to download the address to the nav system. GM and OnStar they're considering that for future versions.

The Destination Download feature costs $2.75 per trip on top of the annual TeleAid contract cost ($240 plus), but that's in cars costing $86,175 (S-Class) and $96,275 (CL-Class). For those cars, quibbling over $2.75 a trip is like quibbling about the cost of yacht fuel. But in case you do care, OnStar Turn-By-Turn costs $100 a year over the $200 yearly cost of basic OnStar Safe & Sound. Other monthly navigation services (cell phone navigation services such as Verizon VZ Navigator) run about $10 a month, so Destination Download would be roughly equal in cost if you used one lookup every week to 10 days.

Expect other automakers to follow the lead of Mercedes-Benz and GM in providing navigation downloads. One solution to the ease-of-use hassles with today's navigation systems is to do the most difficult work for the driver.

To read a review of the Cadillac DTS with the Onstar Turn-By-Turn service, click here.