Michael ,
As well as a few hand tools, and key spares (as others have posted) almost the most important thing is attitude.
Do be sure to take a mobile phone and continental breakdown insurance, just for the piece of mind it brings
If you go with a sense of adventure , keep your plans (e.g. overnight hotels, etc) as flexible as possible, and just treat the road trip as much a part of the holiday as the destination , then you are sure to enjoy every minute of it.
The mini-issues that might crop up on the way will make great memories to share with friends and family (well those that understand at least) and the good part will etch on your memory for ever.
