This is probably covered in this thread but I will give you a check list how to burn MP3's to a CD to play in your car.
1. Choose name brand Blank CD-R's that burn once, not CD/RW's. that can be 'formatted" and reused.
2. There are many apps that convert and burn MP3s', the simplest free app is
CDBurnerXP
3. The wizard starts and asks you what type of disc do you want to burn, choose
Audio CD for music.
4. Select your source drive or folder (USB?) and drag and drop or copy and paste the MP3's into the Burn Windows in the bottom of that window
5. Make sure your CD Burner is supported it should be listed in the middle toolbar in the app.
6. With a blank CD-R disc in, go to top toolbar to Disk/Disk Information, this will tell you if the disc is blank and burnable, not all brands of CD-R are supported by your burner..
4. Once you have selected your files and dragged to the lower window to burn,
5. You should change the Burn speed when you press the
Burn Button to the
Slowest possible, if not, the disc may skip.
After burning, try playing it on another computer or if you have a home stereo or boombox. If it fails, throw the disc away and try it again with another CD-R
Now adays, if you have a Smartphone and your Car has Bluetooth, you can either play songs directly from your USB in your car, or you can add songs to your Smartphone and it will play through your cars audio system via Bluetooth.