Cars get bigger and heavier..

The Financial Times reported that European car manufacturers reduced CO2 emissions from new cars last year at only half the rate needed to meet their voluntary energy efficiency commitment for the European market. Provisional figures for CO2 emissions from new cars show the European industry produced an average efficiency of 160 grams per kilometre last year, down only 1.8% on the previous year. To meet the target of 140g/km by 2008 the carmakers need an annual rate of improvement of 3.3%.

In a separate press release, Jos Dings, the Director of European environmental group Transport & Environment said, “Since the agreement was made in 1998, the car industry has been putting most of its effort into marketing bigger, heavier, more powerful cars...Rather than living in denial about its failure, the industry should support calls for a legally binding, flexible and transparent system that gives real incentives for manufactures to achieve the 120 g/km target. This target is essential for Europe to meet its climate objectives and to reduce its EUR 100 billion per year dependency on oil imports.”

WHAT CAN I DO? Well, a lot, in fact. Chose a more efficient car, use it only when needed, do car-pooling (more people in one car), walk more and use more public transport (it keeps you fit as well!). Even better, write to your politicans demanding better efficiency standards.
If you are in the US, you can write letters to politicians:

Union of Concerned Scientists

Find out more about chosing an efficient car here:

Database of cars and fuel efficiency (including miles per gallon figures)

If you speak French, German, or Italian, try this excellent consumer site

TopTen website