I had a really great 1/2-din casette player in my GTI many years ago. It was stolen along with the CD player in the first theft (when they crowbar'ed my rear hatch). It was a Sony as I recall, and it was really good. It had a drawer that slid out and you laid the tape flat into it.

The model is probably over ten years old now, I'm sure they don't make it any more. But I sure missed it.

Then again, all my tapes got ripped off at the same time, so that's when I pretty much stopped using casettes altogether.