We have a winner! No surprise if you throw enough guesses one will be right but it was Graeme's first shot that pretty much nailed it!
X5 and Smart Fortwo.
X5 is 4.8l V8 Sport with about 350hp and 7 seat option.
Smart is newer 1000cc turbo with 82hp and paddle shift.
The X5 is mine and completely impractical, averaging 13mpg in the month I've had it... I'm really enjoying it though as my first big comfortable car it's effortless to drive, nicely spec'd also with Nav, TV, rear camera, heads up display, independent rear AC, pano roof and lighting pack so the door handles all light up. Don't see many Sports around so the 20" wheels and flared arches make it look pretty mean. It's quick enough and makes a good sound as well but at 2+ tons it's only a 'sport' by name.
The Smart is pretty good fun, with 84hp it's not slow and dynamically it's all quite direct so you know you're driving it, I may have compared it roughly to an Elise/Exige for feel (but it has been 9 months since I drove my Exige and have been driving a Duster and a Yaris since then

).
The Smart will never leave the town and I doubt it will ever do more than 50mph, €35 to brim the tank and expecting it to last a while...
To the other guesses, E90 M3 was always my plan until I saw the roads were terrible quality and opted for a big car. I'm not ruling out in the future a Porsche of some sorts though and an older 911 or Cayman would be what I look for, a colleague has a scruffy 996 that never gets washed but he drives it everyday and loves it.
A quick search on Wikipedia suggests the Smart is Rear Engined and not mid engined like I originally said, so with a non valid clue the prize of free accommodation and transport in Athens is no longer valid either, sorry. Thanks for the participation though
Mike- working for Ocean Rig, was previously in Luanda.