I think custom car audio is problematic from now on.
We got talking about this at last weeks AES meeting in Minneapolis. The discussion was about how fabulous a lot of the stock car audio systems are these days.
The Pioneer system in my Chevy Equinox is first class. I'm certain that did not happen by accident but by committing mega resources to the problem.
It presents a really believable sound stage, with a very smooth response. Excellent voice clarity without a trace of shout. The sub has been well integrated and not overdone. I have used the system felt and have felt not inclination to meddle. The power available would do most AV receivers proud.
It has a 10 gig hard drive you can rip CDs to and download any digital media. There is also a USB input.
I can't imagine any custom installer improving on it. To be honest is sounds better than most of my auditions at Hi-Fi dealers over the last few years.
I suspect the senior engineers recruited away from KEF because of their dissatisfaction with the Chinese owners has paid big dividends here.
Other members said that the sound systems in a lot of Audi vehicles are fabulous. Audi have committed mega resources to improving car audio in recent years.
On the other hand the sound systems in the other vehicles I tested were not very good and the Subaru sound system was particularly dreadful.
However sound quality did not get the lions share of the weighting in decision to purchase. I was just lucky that vehicle come out on top for numerous reasons. I think the audio is also helped by the fact that that vehicle is about the quietest I have ever been in.
Having been involved in car audio from '78 until '97, it really surprised me that it took the automakers as long to get into this area as it did. OEM radios sometimes had a good tuner but that's about all. Then, Rockford-Fosgate became involved with GM because they were tired of people buying the basic AM radio or just deleting it altogether, losing millions of dollars in accessory sales. The hobbyists and manufacturers were doing all of the research for the automakers and then they started including some other electronics in the head unit, like Honda with the security system. That necessitated installers and car owners leaving the head unit somewhere in the car. The old peel & stick begat Dynamat & other brands, speakers, amplifiers and other electronics improved immensely, the car audio contest circuit brought about a lot of really creative solutions, even if they were more brute force than real sound quality, and the automakers were using companies like Pioneer, Infinity, Mark Levinson, Bose, etc for development of higher quality sound systems. I don't remember which company it was, but one guy who won a lot of IASCA/USAC car audio events went to work for Toyota or Alpine Audio because he was so good at designing/installing better systems. At some point, I want to go to a VW dealer because VW now offers Dynaudio speakers on all of their car models with specific upgrade packages.
The car audio industry is far from what it was. It hit $1B in annual volume in about '82 and by '95, it was over $10B/yr. It's just not practical to replace the system in new cars now because A) the quality is much better, B) it's harder to integrate aftermarket into the vehicle, C) it can void the warranty, D) interest in car audio has dropped drastically and E) being an installer isn't going to make anyone rich.
At this point, if someone wants to improve their car's audio system, I would only recommend it for cars that are at least ten years old.