It exists and you can still buy them on eBay and othe similar sites. Slightly older ones pre all the Star Wars designs and lights sound much better.
I agree with Dkarmeli, I don't know of any good ones currently on the market, but there are a few which have recently been discontinued which are very good.
Look at any of the following:
Pioneer - DEX-P99RS - this still may be available, but I'm not positive. I have one and it's fantastic.
Nakamichi CD700II - easily the best head unit I've ever heard and also own one. It's long discontinued however.
Do a google search of "DIY mobile audio forum" and you will find the Audiogon of car audio.
I managed in the auto components sector for many years. The money is in OEM. When I was with Delphi, we had a relationship with BOSE and Sonigistix (Monsoon audio). Back then, the premium system were just speakers while we (delphi) built the head units (or we sub contracted to Pioneer), amps, etc. BOSE would provide Powered speakers which would be hooked up to a standard head unit (GM Cars). The 1999 Corvette I owned had the same head unit found in a Chevy Lumina with powered BOSE speakers.
Nowadays, I'm not certain how everything is done.
One of the big problems right now that is depressing that market is the integration of the audio electronics with the rest of the computing power and electronics of the car. Most of those systems are proprietary so the days of just swapping in a better head unit and set of speakers are over. The factory amplification may employ built-in DSP & equalization so that you have to compensate for that, as well. My BMW required an expensive "adapter" (nearly $1K) to go between the factory head unit and the aftermarket amplifier, which also had to have adjustable EQ built in to compensate for the difference between the response of the factory amp/speakers comob and the amp/speakers I had installed. My wife's Audi does not even have a head unit per se. The display is built in to the infotainment system,w the display functioning for GPS, audio, bluetooth/phone, etc with all of the controls on the steering wheel and on the center console.. You'd have to cut a hole in the dash somewhere to add a head unit and you know that ain't happening! FWIW, her factory unit sounds pretty darn good.
@swampwalker - nailed it. I just got my dad’s 2008 Infiniti EX35. Wonderful, fast, quiet, and fun to drive. But the Bose stereo system "Blose", even when used with a portable FiiO music player into the aux input. The problem is the integration. You cannot replace the head unit.
I think the best way to go, if you are spending some cash, is to find a good installer, one who focuses on sound quality, not dB levels, and use one of the aftermarket DSP units that flattens out the audio out of the head unit, and allows you to install your own amplifiers and speakers. You still have some reduction in sound quality from the head unit, but it’s the best you can do if you can’t remove the head unit.
Before the Infiniti, I had a Subaru Outback VDC with the McIntosh-designed, Clarion-built in-dash CD changer. No aux in, but it sounded excellent. Too bad the car suffered from high amounts of wind noise, so that at highway speeds, you couldn’t really appreciate the McIntosh system.
Somehow the "premium" systems (power, subs, blah blah) in both my '09 BMW and new turbo Mini work well, with the MINI using only bluetooth signals (a cable from my phone is required for the BMW, although calls are wireless…weirdly). Both cars have enough tone control to make them sound fine, but hey…it's a car...