MPG - if it bothers you then you probably cant afford the tax & ins. anyway.
If you do a lot of Motorway miles you want a car that gets good MPG
My Dad has a 1.9TDi Laguna Estate and gets roughly 57-58mpg at 60mph in 6th.
Even at 100mph in 6th his revs are under 2.5k and getting 45ish mpg.