Hi Dave,
I have not heard of any CD but I have looked on I-Tunes before now. I dont know if this is an option for you i.e. if you dont have an ipod, then perhaps you can write the poscasts to CD and play them in your vehicle. (Hopefully your car has a CD player and not a cassette deck!).
On I-Tunes I found a podcast called "Diabetes: Into the New Decade" - it is a little old fashioned in places regarding things like how to use a blood sugar test meter - but the principals are still good. If you are new to diabetes, it is somewhere to start.
I also dip in and out of an American podcast called "Dishing Up Nutrition" with a lady called Darlene. Although american orientated, it quite good to listen to and they make healthy eating sound alot of fun - more than some of the sources in the UK do anyway. This podcasts covers many areas of nutrition and is not specifically diabetic related, but never the less.
As you are on the road a fair bit then internet access may be a bit limited / complete rip off for few mins / high costs and therefore logging onto the web/this forum may not be te best use of your internet time. When I was diagnosed I had really limited access to the internet and was relying on a 2G wifi dongle. I ended up buying a tablet and downloading two/three books relating to diabetes with the kindle app so that I could look things up. (It costs me E50 per visit to the doc - I had to work out things for myself - the books really helped me).
Hope this helps,
Eater of Ants