Thanks for the welcomes....
Picked the car up this morning no problem, about 10 miles down the motorway the engine warning light came on and a "motor drive failure" message. I immediately pulled over. Phoned the dealer they asked me to gingerly drive the car back as it still seemed to be functioning. Managed to get back to the dealer ok, they checked it out and said they had found an intermittent fault on the turbo and had fixed it.
Got back on the motorway, about 25miles later the engine light came on again but this time had lost nearly all power, i could barely maintain speed on the motorway, no black/white smoke out the back though. Rang the dealer again and agreed to take it back. Really struggled on the way back, especially uphill where it couldn't even maintain speed, quite embarassing really.
Anyway, arrived back at the dealer and they're going to look at it first thing monday, i have a courtesy car until then. Definitely something wrong with the turbo, maybe a broken inlet hose or something. I'm very disappointed but i guess it's one of those things
Car was great for those first 10 miles though, everything i expected.