Yes Yes Yes And Yes
Here's a link to a map with distance and directions from London to Hinckley.
http://maps.google.com/maps?q=Hinckley,+UK&sa=X&oi=map&ct=title
I think you have to make a reservation before you go to insure getting in. If I remember correctly, there's only 2 tours a day and limited to around 20 people. I think you can make the reservation through your local dealership or directly to Hinckley.
As to other spots to visit, you can never go wrong with the traditional ones.
Buckingham Castle
Big Ben
Parliament
Westminster Abbey
Tower Bridge
Tower of London [ Crown Jewels, Ravens, Beefeaters ]
London Ferris Wheel
You can also catch buses for 1 day jaunts into the countryside:
Stratford Upon Avon [ Shakespeare's Home ]
Windsor Castle [ Royal Carriages can be seen in the livery stable ]
Just remember...... As a driver and especially as a pedestrian, your first look at an intersection is RIGHT !