That was actually the wrong question.
I didn't really want to ask "why do you need two cars," I wanted to ask "do you need two cars?"
Running a car is a pretty big expense. If you're trying to reduce outgoings, it'd be the first thing I'd be looking at; can we manage with one car and the occasional public transport? The answer may well be "no" of course, but three miles in a taxi should be, what, 25 quid a week? Does the car cost less than 100 quid a month?

