Thanks for your reply Alan.
Sorry for the delay in replying but I've only just started the process of installing the rig in my car. I'm at a halt just now as I'm sourcing some waterproof CAT5 connectors.
As you can tell, I'm not in any desperate hurry!
I've only powered the rig up yesterday and a few observations:
1. The clock gains time - 3 minutes overnight.
2. The temperature shows 33c - in the UK we don't get that in the summer!
These are minor 'problems' but problems I'd like resolved anyway.
As I proceed with the installation I'll update this thread.