Upgraded car shocks, mufflers and brakes are something you would expect from a souped-up car, but how about an actual, custom computer? Thousands of extreme car-modders already are installing complete computer systems in their vehicles for GPS, music playback and even Internet access. Members of the mp3car.com forums recently got together in Huntington Beach, Calif., to show off their electronic vehicles.

Car computers generally run Windows XP and have a graphical front-end that enlarges the buttons and unifies the mixer, video, music and GPS functions. There are different front-end software packages and most are freeware. The large buttons are not just for looks as Robert Wray from MP3car.com told us that "the enlarged buttons are a safety feature because the default size is very small on a 7" screen." The screen of choice is usually a touch-sensitive 7" or smaller LCD monitor.

People have been installing LCD screens and video game systems into cars for a few years. It's not uncommon to see SUVs that have an LCD screen on almost every surface, but car computers are much rarer. One of the growth barriers of this segment is the fact that there is no standardization for car computers. As a result, enthusiasts are using almost any computer available and find innovative ways to connect the PC to the battery. Some people have used shoebox-sized PCs in the front of the car, while others use a full-sized desktop PC in the trunk.

MP3car.com is trying to change that by selling car specific PCs, monitors and other parts. Wray told us that the website doesn't make that much money from the sales and only "pays a little bit for our bandwidth." He considers the real benefit of the site the discussion forums, which currently has more than 26,000 members and about 657,000 posts.

So what have people done to their cars? We spoke with Roy Liao, owner of a 2001 Toyota MR-S, about his "stealthy" car computer. At first glance, Liao's car looks ordinary except for the extended head-unit that contains a 7" LCD screen, but behind the radio controls sits a VIA M10000 computer and a CD-RW drive. Liao ripped out the guts of his stock radio system and re-encoded the buttons and knobs to control the computer. He even connected the window-lock button to reset and turn on the computer. "This is a two door and it didn't make sense to have window locks," says Liao.

According to Liao, he spent several days installing the computer, but he feels it was well worth it. "This is my baby and I can't imagine driving without a car computer," says Liao.

Another car-modder who goes by the name of DJik on the MP3car.com forums has a 1998 Mitsubishi Eclipse GSX with a Pentium 4 2.4 GHz computer in the trunk. Unlike Liao, DJik placed his LCD screen down by the gear-shifter instead of on top of the dash. An ingenious and very inexpensive pull-down cloth shade protects the screen when not in use.

Among some of the improvements to his car, DJik ran a USB extension cord just above the ignition switch, so he can pop in his USB flash drive and transfer files on the go. A front and rear-facing camera can record video and DJik told us, "If anything bad happens, I have video to prove that I was right." In the trunk is a wood-encased PC with a 160 GByte harddrive. Next to the PC is a wireless adapter that runs NetStumbler to find available access points.

What's next for the car computer? Wray is currently building a show car with a high-end processor and video card that is capable of playing 3D games. "We should have no problem playing World of Warcraft in the car," says Wray.

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