Car audio competitions are relatively popular, so you shouldn't have any trouble finding one. Several organizations hold contests across the United States multiple times per year, so you probably won't even have to go too far out of your way to track down a sound-blasting arena of amazing audio setups. These groups include the International Auto Sound Challenge Association (IASCA), the Mobile Electronics Competition Association (MECA), TermPro and the United States Autosound Competition International (USACI).
Each group holds its own competitions, and most of them require membership to take part in sound quality and sound pressure contests. For example, registered IASCA competitors can take part in a range of challenges beginning with the SQC, or Sound Quality Challenge. The SQC is broken up into seven classes, ranging from rookie to expert solo. The SQC challenge is designed to gauge the quality of your sound system under real-world conditions and judges audio based on tonal accuracy, sound stage, imaging, sound linearity and absence of noise [source: IASCA]. Another example, the IASCA Bass Boxing contest, lets competitors play music in their cars and earn ratings based on the average decibel level produced by the subwoofers [source: IASCA]. Each group has its own rules for competing and different challenges for its members. Check them out and see which ones interest you -- then find out who holds events in your area.
Wondering who's going to be competing against you and judging you in these events? Basically, people who love car audio. IASCA trains its judges with the rules written by and for its members. The IASCA rules even suggest certified judges aren't there to evaluate your car and score it; they're there to help you improve your sound system. During a competition, they can't say much to you, but when the show is over, don't be afraid to ask them for their input regarding your sound system. If you're lucky enough (and backed up by a beastly sound system) you may even be able to win a cash prize at a car audio event. Even if you don't win, though, you can solicit advice from other audio fans and rest assured that all those audio upgrades will be put to good use -- your music will sound absolutely amazing coming through your top-of-the-line system.