The car environment is certainly a challenge to experiencing a high end audio sound, but it can be done. Most good cars have good enough electronics and speaker placement so that is not the primary problem.
The big problems are all those glass windows , road noise, quality of the source of music and electronic noise from the power source.
I treated my car's interior with the family of Synergistic Research HFT products. It now has about 15 of the various HFT's placed using Synergistic Research's diagram for a room in a house. Big improvement.
The windows had already been tinted with a plastic film which makes a small difference. This included the front window that has a clear tint (legal to have on a car) that is there primarily to block the hot infra red rays of sunny New Mexico. The window film decreases that glass window bad affect on reflected sound.
After the noticeable effect of the above two improvements, I looked at the electrical circuit in the car. Using the Perfect Path Technologies Total Contact product, I treated lots of electrical contacts. Just treating the car's battery terminals was a major improvement. All these connections are a poor mixture of different non audio grade metals. Making the car's ground return a metal to metal contact gave an improvement.
I then added a Stein Music Harmonizeer to the car. This generates a very low frequency radio wave that helps to combat all the high frequency cell phone 3G-5G noise that is disturbing our electronics.
Lastly I upgraded the front end source by streaming music (first Pandora and now Qobuz) from my cell phone to the music system. Unlike three years ago, I am no longer having drop outs while driving in the car and streaming music.
My car now has a wonderful 3D soundstage with a relaxed flow to the music. By lowering the noise the emotion and detail of the music can be appreciated. Commuting to work is now much more enjoyable and relaxing.
David Pritchard
