No matter what might go wrong with the car I'm confident that I won't be able to fix it. Hence I'm another who's list starts and finishes with a mobile phone.
I once managed to ride a motorbike to the Pyramids and back with this philosophy and it served me well, whereas I encountered a German biker in Luxor who was carrying so many spares and tools (including wheel and complete clutch) that the weight of all these bits 'n pieces broke the frame of the bike when flying over a sand dune. How I chuckled. (Can't see myself pottering through Syria again any time soon - I hear it's a bit of a pickle down there these days.)