Slowly
May not be useful now but in 2005 we rented a reasonable car (3000 miles new, 4cyl diesel) from easycar (
Car Hire in London - Compare cheap rental deals from easyCar) for £2 a day plus insurance etc. Cost about £8 per day with unlimited miles and insurance. Catch was it was only available from one location (Stockwell) and from Monday to Friday only.
Geof