I think the car audio upgrade market is built around teens with money to spend. Unfortunately, teens often think higher price means higher quality ("Dude! Check out my tight new BOSE system!").

Really, I think the whole world went to sh*t (I'm only half-serious here) once teenagers started to have a lot of discretionary funds.... Their influence knows no bounds. They've affected the music industry, fashion industry, entertainment industry... I could go on.