How to make an mp3 cd for car stereo?

My car stereo supports mp3 format. I've made cds through media player and similar programs that use mp3s and have been able to use them in my car. What I am trying to do is make one of those cds that has like 100 - 150 songs on it instead of just the 20 - 30 that will fit when using one of the standard media programs as a wizard. I'm trying to get down to two or three cds instead of carrying around two dozen. Also, I'd like to have the folder structure so I can easily find things. (This is also supported by my player - http://www.saturn.com/assets/en/pdf/owners/manuals... , page 159).

What I did was inserted a (new) blank CD-R into my computer and did the drag and drop feature that Vista has for burning cds. It seemed like the process completed alright, but then I go to play the cd in my car and I get "Disk Error" and it pops it back out at me. I dont see the problem here. Player supports mp3 format and HAS played them in the past, and it supports the folder structure, but it wont recognize the disk. I should also note that the disk WAS finalized before attempting to play it.

Does anyone know what I am doing wrong?