finished finally the course and then followed Jonathans another course on the headphones with lighting. Obviously the black background doesn't work that great with this kind of model, would need clear skies etc. but i think thats enough with this one for now. have to continue the other courses aswell.
also the final render times. i'm using 2.72 atm and if i put 1000 samples it did 4 tiles and kept there for 30 minutes after which i started to tweak the sample settings.. which i realised that if you put 1000 there it was somewhere along 100k samples.. :) this one is with 40 that totals for 1600. might do higher ones later to see if the noise on the back of the plane goes away. or with completely different background.
Thank you Jonathan for excellent tutorial! learned lot of things. and small tweaks that will help me further.
cheers!