Just clearing up a point .....

There are actually two separate train sevices that go via the Eurotunnel/Chunnel:

The Eurostar - This is the passenger train that runs a regular service linking stations at London Waterloo, Brussel Midi, Paris Gare du Nord, Ashford International (in Kent), Paris Eurodisney, Calais Frethun, Lille Europe, and also in the skiing season trains are laid on the the Alps. The train itself is decked out in a lurid yellow and grey motif, and regular passengers get planted in the most uncomfortable seats in the world. The service generally runs late, but the staff make up for it by breaking out the free champagne (when we pointed out that our CEO was on the train and he had booked the entire thing for the 500 staff to travel across).

Le Shuttle - This is the car transport service that runs in direct competition with the ferry services. It operates between Folkstone and Calais, and runs once every 15 minutes at peak times carrying 120 cars and 12 coaches . Passengers drive onto the train, and drive off 35 minutes later on the other side of the Channel, without ever having to leave their vehicles