In reply to Shoski:
Back when I hung out at Mile End wall (20 years ago!), the thinking in the pub on a Wednesday evening was that London was the best place in the UK to be climber, because if you wanted to climb you _had_ to travel, and thus you would go all over the country - the Peak, Wales (North and South), the Wye Valley, the south coast, and then occasionally further away to Cornwall and the Lakes and Yorkshire and Scotland. By contrast, if you lived in Sheffield you just climbed in the Peak all year - ergo, we were better off in London. At least, that's what we told ourselves!
To your question, for a climber in London, a car is a no-brainer. I had a Passat estate which I bought for a grand from some bloke in High Wycombe. It was a cracking crag car, and had the benefit of being quite comfortable to sleep in. I drove all around the country in it, and it even took us to our new home in Spain, after which the gearbox gave up, and it now rests sunbathing in a scrapheap somewhere near the Med. Ah well. It had a good life!
edit: you will learn to hate the M1 on a Sunday night though.
Post edited at 16:39