Thanks Canman ! I've done I don't know how many oil changes on my smart and never put in more than 2.5 litres. Did the oil change as per usual and no leaks. Took it for a good run(60 kms) and still no leaks. I'm a happy man. It was obviously overfilled. Screwed up somewhere. Was fearing the worst.....new intercooler. Anyway, thanks for pointing out the obvious.