There are no major audio companies currently producing "2 shaft" radios.  Most modern car audio is a "din" or "double din" mount.  In order to fit these to your classic car, you'll have to cut a gaping hole in it.  No one wants to do that to a classic car.  Modern speaker systems are designed to acoustically complement the particular characteristics of the car for which it is designed.  Amplifiers are used to augment the sound so that the speakers are driven at their peak efficiency.  It is simply impossible to accomplish an "audiophile" level of sound quality without major modifications to your valuable collector car.   
 
The radios shown here are made in a basic chassis that is altered to fit your car.  No modifications are needed to your classic vehicle.  Speaker systems are designed to fit many different locations and situations, again without altering your car.  These are a nice compromise, but are by no means "audiophile" quality systems.  They will not sound as clear as the stereo in your new car, or shake the car on either side of you at the next stoplight.  An in dash radio and a small dash speaker cannot produce this kind of sound.  They do provide a reasonable level of sound quality that is acceptable to most classic car collectors. 
 
Additional amplification and better quality speakers, as well as an iPod or a MP3 source will greatly improve the sound quality of these systems.  The better the source of your music, the better it will sound.  If your car has provisions for a standard size speaker (for example a 6x9 in the rear deck), your sound quality will be much improved by purchasing brand name speakers and an amplifier that suits your particular listening requirements, while still maintaining the integrity of your vehicle. These speakers and amplifiers should be purchased from your local car audio dealer, where they can be auditioned prior to purchase.

The system I am currently running in my 1965 Mustang, is centered around a RetroSound Model One head unit.  I have a 4x10 Dual Voice Coil Speaker in the dash, and a pair of Polk Audio DXi690 6x9 Speakers in the rear deck hidden by a pair of Custom Autosound's plain flat speaker grills.  The front speaker is powered off the radio, and the rear speaker are powered by a Rockford Fosgate Punch P500-2 Amplifier.  I play MP3s from a USB Flash Drive, and listen to mostly Classic Rock & Smooth Jazz.  I have been in the Home & Car Audio business since 1977, and I am very satisfied with the sound quality, the looks, and the fit of this system in my classic car!  This is just an example of what you can do at a reasonable cost, and without altering your car!       Jack Wolff - Grand Rapids, Michigan   Owner, Great Lakes Classics