I am looking for something with a bit of space and a bit faster than my Mondeo.

So current car.... Mondeo 2.5 V6 24v automatic. Good points, ultra low miles at 71k and there is nothing wrong with it, plus parts are cheap and very easy to source second hand....Bad points, not fast enough and economy is poor for the performance at 23mpg (country road/B road driving)

Been looking at the Lexus GS430 auto. Good performance figures and looks spacious with lots of creature comforts....But! Will it cost me a fortune to run in fuel and parts? I do mostly country lane/B road driving.