Here a some good Internet Car Audio stores.
Zeb Audio (www.thezeb.com) Very reputable place one of the most popular online stores. Really good prices, price matching and good customer service.
SoundDomain (www.sounddomain.com) Not always the best prices here, but they match prices and have sales or price reductions, and you can get a great deal.
Nexxon (www.nexxon.com) MANY products and MANY brands, good prices
Ebay! (www.ebay.com)
MMexpress www.mmexpress.com Similar to nexxon, many products and nice prices.
Car Stereo Mall (www.carstereomall.com)Many good brands available, good prices, and nice extras (such as free amp kits with purchase of amplifier.)
Carmedia1 (www.carmedia1.com) Some of the best price on the net, for many good brands. Also good prices on accesories, even a few car products.
KnuKonceptz (www.knukonceptz.com, or search for the seller KnuKonceptz on ebay) For the ends and odds that you need, such as power wire, rca's, distribution blocks, fuse holders, and amp kits. Really good prices.
Online Car Stereo (www.onlinecarstereo.com) Brands such as JL, hifonics, Dynaudio, Rockford, Pioneer, MTX, and alpine. Good prices and good sales.
Ikesound/Scala1 (www.ikesound.com) also known as seller scala1 on ebay (his ebay store http://www.ebaystores.com/id=7779378) MANY people have bought from this guy. There are a couple of reasons for this: Excellent Prices, and Excellent customer service. You can call him up and he'll work out a deal if your looking for a complete system.
Buyloud www.buyloud.com Good for brands that you can't find on other sites, such as crossfire, McIntosh, and Diamond Audio. Decent prices, Sale prices often good.
High Voltage Car Audio (www.hvcamn.com) If your mirror isn't shaking You got ripped off!! Store run by the infamous Mr. Brownstone. He carries nothing but the best on his site. Not always the best prices, but good deals available sometimes, and he is a seller that will help you not only get your products, and try to help you get them installed as well.
Crutchfield www.crutchfield.com The best customer service on the net, the worst prices. Not always the best place to buy products, but occasionally you can find a great deal (for example a headunit for $300 found elsewhere for $500). This can be a great resource however, to find out what will fit in your car.
But dont just take my word for it, Always ask for opinions of stores on a few forums, such as this one, Car Audio Knowledge (look in links), Soundillusions, and to a lesser extent, Car Audio Forum, SoundDomain's Forum, and Termpro.
You dont really need to ask about crutchfield (if they do have a deal) and zeb audio, or scala1, but its makes you feel better to hear good experiences people have had, or bad experiences so you know which stores to avoid.
-Steve
