Driving around one of Europe's biggest and most congested cities can be a real challenge. Although public transport is quite effective, its still slow and you have to deal with all the announces that comes with it. Although I would not recommend you do sightseeing by traveling in a car, you might need a car to explore some of the fantastic villages and sights around London. The prices for London car rental can vary greatly depending on certain factors. Here are some tips to help you get god value for money.Pickup and Drop Off LocationsWhere you pick up and where you drop off your rental is an important consideration. Anything in central London tends to be more expensive and the fact that it can take you an hour just to get from one end of the city to the other means time is another factor to consider. Look into picking up and dropping off as close to you arrival and departure points. It will save you time and save you money.Airports and Train Stations To and From LondonDepending on how you get to and from London, the good thing is that all the major airports have all the major car rental companies. The problem is that the airports tend to overcharge you and one simple way to overcome this is to take a train from the airport into any of the major stations like Waterloo, London Bridge or Euston and then pick up your car there. That way you will already be in the city center.London Congestion ChargeA big consideration when you rent a car in London is the congestion charge. Its basically a toll that every car needs to when they drive into central London. Its currently 8 pounds per day and it is pretty expensive. You can shop around different rental companies to try and find rentals that include the congestion charge. Usually rentals from onside the congestion zone will waive the charge and if you are really clever you can pick up in the zone ad drop off outside the zone.For more car hire tips and information about London car rental, see my website.