Why does my burned CD sound so much different than my Project file on computer?

I have a perfect mix in MY Project. It sounds great on my computer/studio speakers. I bu a CD, play it in my car or on my stereo and it is entirely different...."thin" and aoying...it is frustrating to edit my Studio One mix, bu a CD, go to my car, take notes, try to adjust...repeat over and over! How do you mix it right for your end user????