Brown said everyone needed a better stereo in the 1990s. Factory radios were lousy. But the aftermarket stereos that people bought to replace the factory-issued ones could easily transfer from one car to the next. For example, if thieves steal the factory stereo from a Volkswagen Jetta, they're going to need a buyer with a Volkswagen Jetta, and all a thief can offer is the stereo the owner had to begin with.
Factory stereos got good (and complicated). Aftermarkets got cheap.
I'd be more concerned about what the author only mentions in passing: They gained access to private customer information relatively easily. This has become such a huge problem in recent years. These sort of hacks and data mining is what the majority of cybercrime is based on these days, other crimes are downstream of it. Companies have too much of our personal information and they're not doing much to protect it.
I'm not so sure about that - I used to have some fancy cars in the past and I've heard many stories from people saying they've been followed to car parks, home, or had only the keys stolen from their home and nothing else - fancy high end cars are almost always stolen "on order" and not by opportunistic thieves. These are the kinds of people who will research what is needed to take your car before they come to your home.