Does your car stereo support MP3 mode? It ought to, since most of the stereos from the past few years have this as standard. If it does support this, all you have to do is burn the songs onto the CD, by directly copying them, and they will play properly. You can even choose the song easily.

Do not burn an audio CD ... this is what Windows Media Player did, and while this disc is playable on any CD player, you can only fit 16 odd songs on a disc. You can either choose Data CD from Windows Media Player or use Nero, and drag and drop the 70 files onto the disc as a Data CD. This will work, as long as your stereo supports MP3 files.