Non-Lcd Display Head Unit Rockford Fosgate RAV DVD1 AM/FM/CD/DVD Receiver $900Why You Need It: Stunning good looks, exceptionally well-designed controls, excellent sound quality, all combined with all-format playback capabilities.Information:Rockford Fosgate, (800) 366-2349, www.rockfordfosgate.com

Signal ProcessorAudiobahn ADD51T Dolby Digital Signal Processor $700 Why You Need It:Add 5.1 multichannel Dolby Pro Logic II, Dolby Digital, or DTS to most systems with Audiobahn's versatile half-DIN signal processor.Information:Audiobahn, (714) 690-7530, www.audiobahninc.com

Enclosed SubwooferBazooka CS8A5 8-inch subwoofer with built-in 200-watt five-channel amplifier $300Why You Need It:Extremely clever upgrade solution that adds an enclosed 8-inch subwoofer and a powerful five-channel amplifier in a single, integrated enclosure.Information:Bazooka/SAS, (800) THE-TUBE (843-8823), www.bazooka.com

Navigation Head Unitharman/kardon TrafficPro AM/FM/CD/GPS $1,500Why You Need It:Brings voice navigation to the masses by eliminating unnecessary features while not requiring a separate changer for simultaneous CD playback.Information:harman/kardon, (516) 921-TPRO (921-8776), www.hktrafficpro.com

Mono And Stereo AmplifiersXtant 1.1 Amplifier $200Why You Need It:Compact size, courtesy of its digital design, means that Xtant's new 100-watt 1.1 amplifier can be used as a building block for complex systems.Information:Xtant, (888) 44XTANT (449-8268), www.xtant.com

Rear Seat EntertainmentSavv LCD Headrest Monitors $600Why You Need It:With a crystal-clear picture mated with one of the widest selection of ready-made LCD headrest monitors, SAVV has just the right video for your rig.Information:SAVV, (562) 529-7700, www.savv.com

Multichannel System AmplifierAlto Mobile GD 600DSP $1,000Why You Need It:Highly efficient digital design means a "fit anywhere" chassis; six channels on board means it can power an entire multi-channel, multimedia system.Information:DANEX, (414) 423-5430, www.altomobile.com

Integrated Drop-In Replacement SpeakersPolk AudioPolk/MOMO Series $150 - $240Why You Need It:Same sound quality that we found last year in Polk/MOMO's separates is now available in a line of integrated, drop-in replacement speakers.Information:Polk Audio, (410) 358-3600, www.polkaudio.com

Four-Channel AmplifierAlphasonik PMZ6004 Four-Channel Amplifier $350Why You Need It:Low-profile design, generous 200-watt output, and optional remote digital voltmeter make Alphasonik's PMZ6004 four-channel amplifier an outstanding upgrade.Information:Alphasonik, (714) 988-0370, www.alphasonik.com

LCD Display Head UnitAlpine IVA-D900 AM/FM/CD/DVD Receiver $2,300Why You Need It:The sharpest, clearest retractable screen built into a head unit that can serve as the control center for the most comprehensive system imaginable.Information:Alpine, (800) ALPINE-1 (257-4631), www.alpine-usa.com

Component Separate SpeakersBoston Acoustics Z-Series $1,000Why You Need It:High-performance, high-excursion design with a state-of-the-art crossover; goes lower and plays louder than traditional door-mounted speakers.Information:Boston Acoustics, (978) 538-5000, www.bostonacoustics.com

Radar/Laser DetectorEscort SR7 Remote with ZR3 Laser Shifter $1,600Why You Need It:Simply the best, most comprehensive front and rear radar/laser-detection and laser-jamming solution available, at any price.Information:Escort, (800) 964-3143, www.escortradar.com

Satellite RadioKenwood KTC-H2A1 Here2Anywhere Portable Sirius Receiver $130Why You Need It:With the addition of an easy-to-install vehicle kit ($70), it's now possible to take 100 streams of Sirius satellite radio with you wherever you go.Information:Kenwood, (800) KENWOOD (536-9663), www.kenwoodusa.com

Mass Storage Mp3 PlayerDension DH101 AM/FM/HD Receiver $800Why You Need It:Offers the ability to store hundreds of MP3 files on its removable hard drive in a DIN-sized package that can be installed in almost any dashboard.Information:Dension USA, (866) 822-DMP3 (822-3673), www.densionusa.com

Component SubwoofersJL Audio 13W6v2 13-inch Subwoofer $600Why You Need It:JL Audio transfers many of the top-of-the line W7's performance attributes into a small box, install-friendly format in a unique 13.5-inch driver.Information:JL Audio, (954) 443-1100, www.jlaudio.com

2003's Top Factory Demo Truck Polk/MOMO '02 Ford EscapeWhy You Need It:While there were many outstanding factory demo trucks on the circuit in 2003, one that stood above the rest, combining innovation, flexibility, and sonic excellence, was Polk Audio's '02 Ford Escape. Showcasing a unique center channel setup, installers Thom Voisinet and Josh Claar illustrate that it's possible to fully integrate a dual center-channel speaker array for full 5.1 multichannel surround sound. Information:Polk Audio, (410) 358-3600, www.polkaudio.com