Let me tell you a little story. There once was a young kid who eat dreamed slept 12 volt car audio. He needed a secodn job to help pay for his cool toys so he applies at a circuit city roadshop. Gets hired. realizes that its not nearly as much fun to do a system their then on your own. Completely kills the drive to work on anything car audio related. This was me about 7 years ago. Now my motivation is gone. At first it was cool adn I learned an immense amount about just about every aspect except fiberglassing but I never had any desire to work on my own car after dealing with customers all day and spending hours jammed under the dash of a car doing an alarm remote start. we always had idiots for installers that could do a deck and four and if you were a good installer you were doing the alarms and remote starts video systems etc.
In other words. if you like it as a hobby keep it as a hobby.