Car appreciation... the aesthetics, the engineering, etc

As your first car to you and your wife, I'd say don't buy anything too pricey. Buy the smallest and cheapest car while you both get used to drive in London. There is more to driving than just passing the test. You'll find the experience comes from doing lots of hours behind the wheel. As new drivers I'd recommend a small engine cheapo just to cut your teeth on. Don't spend thousands on your first motor.