Is there an audio CD Remedial Grammar course with drills?

Can anyone recommend an audio CD EFL grammar course for an adult businessman who has 2 x 2 hours/week at the wheel of his car and thus can listen and practise grammar?

I am not looking for a multimedia CD-ROM or audio CD with cross-reference to a printed book. The CD must be entirely aurally-based. He has no time or inclination to work at any other way of learning grammar.

Thanks in advance.