Have you ever tried to learn a foreign language from those cassette and book sets?

Question

I'm trying to get a head start learning Spanish before the new semester starts. I went to the library and took out one of those "easy learn while you drive" language sets which include 4 tape cassettes and a lesson guide. After playing the lessons over and over, I find that I have almost no retention of the language.
Am I doing something wrong or are these sets ineffective?
Any advice will be appreciated.

Answer 1

Yes...and I found a great on in the library for Portuguese..I cannot remember the name of the co. who put it out. Sorry.