If anything, 2003 was a benchmark year for innovation in almost every mobile electronics category. From head units to subwoofers, never have more component choices been available. More importantly, better products, with improved performance and enhanced feature sets, cost less than ever before.

In the head unit category, MP3 capabilities have been included on all but the most basic receivers - not that Sport Truck readers actually look at entry-level components. And as we've been predicting, with the downward spiral of DVD transports, we expect to see more in-dash DVD receivers making an appearance in 2004, with units from well-known manufacturers making an appearance later this spring at prices that will establish new benchmarks.

Related to DVD developments in the in-dash category, units with integrated LCD screens continue to gain traction in the marketplace, in spite of prices for full-featured units with built-in screens remaining in the more-than-$2,000 price category. While there has been some downward movement in price, the popularity of these units means that this is the one category that manufacturers have less incentive to move prices lower. We expect that at the 2004 Consumer Electronics Show several manufacturers will introduce new models, some with built-in DVD transports at prices that might approach $1,500.

Powered by awareness on the part of the vehicle manufacturers, rear-seat entertainment has gone mainstream. While on the OEM level, overhead monitors dominate, in the aftermarket, headrests with monitors pre-installed offer additional options. Some are so easy to install that they fall into the do-it-yourself category and are sold by mass merchants rather than specialty dealers.

In the signal processor category, multichannel sound remains the buzzword, and the Dolby Digital format has become the de facto standard much as it has in the home. Multichannel sound provides five discrete full-range channels and a separate channel dedicated to low-frequency reproduction. In addition to signal processors, we expect to see this capability to be integrated into an increasing number of mid- and high-end head units starting in 2004.

While not a glamourous category, there was big news in the amplifier segment as high-efficiency digital amplifiers are no longer for subwoofers only. Manufacturers have mastered the obstacles in building digital amplifiers that can accurately reproduce full-range signals up to the upper limits of human hearing. While the number of amplifiers in this category in 2003 was small, its advantages, such as a compact size, are undeniable, and we expect this will be one of the primary mobile electronics product trends in 2004.

As in almost every other category, 2003 saw speakers offering better performance at lower prices. Both integrated speakers and component separates now offer greater power handling capabilities, which is important as more powerful amplifiers become available. Massive drivers continue to make waves in the subwoofer category as several manufacturers have taken technology from their leading-edge products and applied them to more mainstream products.

Navigation remains a niche product, but there is some good news on the horizon. The technology is getting less expensive and the components smaller. This means that the next trend in navigation will be to integrate full voice navigation capabilities into single DIN-sized units. The first of these units was introduced in 2003, and we'll be watching to see if this spreads to other manufacturers in 2004.

With thousands of components to choose from, choosing the best in each category has been exceptionally difficult this year. While not the last word, we feel that this year's selection represents a meaningful balance between performance and cost, giving our readers a great starting point in building the ultimate system for their trucks.