Hi PeterD,
Thanks for your reply.
I have been doing a bit of surfing and I think that I have found the same product as the one that you have, available from a UK supplier through Ebay. Take a look at the link:

http://cgi.ebay.co.uk/LED-LENSER-12v-Car...=item43a14373dd

I can see that there have been many good reviews of this particular product, but it seems that the adapter does not fit very well in some makes of cars. It seems that in some cars the contacts can become separated easily through vibration and bumps in the road etc.. One has also caught fire ! (not good in a car made of wood !! exting )
If it is the same product, Peter, take care that you don't leave it plugged in all the time, just in case.

Jaguar F-Type V6s roadster
2009 Harley Davidson XR1200
1986 Honda VFR750F (RC24)