For a car stereo shop to survive, they need to sell everything entertainment: Home audio, car audio, window tint, home installation, car installation, custom car and home installations, lighting, security, security monitoring, spray-in bedliners, on and on.
This is why wal-mart is so successful.
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-2000 Toyota 4Runner Limited 4WD Supercharged (silver/black, heavily modded, Team JBL)
-1991 Chevrolet Corvette ZR-1 (red/gray, stock)
-2004 Sentra SER (yellow, stock)