Sorry its a bit of a late reply! Im hoping its just a bit of water! Its not there all the time from what I gather. My car was iced up this morning and by the time I got to work (about 9 miles) I saw steam coming from the front which in a way could easily be water i guess.
Way home it was there when I parked but wasnt constant, just a few seconds!
As for the knocking... its not dangerous for me to drive is it? lol im scared to go anywhere!!! I know several people have had it
Damn early MINIs! Wish I went newer... I keep gettin moaned at by my parents about havin a MINI and I should get sumin else etc... but I dont want to! Love the car and its great to drive