vapour out exhaust

[wjwren]

any of you chaps had a similar issue? My 645 is quite "steamy" out the back. Ive never really noticed but had the tyres changed this week and while it was on the ramp the bloke said jesus she smokes a lot. Then was sat in traffic and notice smoke or steam not sure which was drifting past. This isnt just after short journeys either, but after 25 mile run. The car doesnt use any coolant and there is no coolant in the oil. Both pipes seem to have fair few droplets of water on.
Any clues or do BMW's just like to smoke!