As above, it's largely down to dealer descretion. If it was done at the right time and the right things were done then it is within their guidelines. Having said that, I very much doubt they'd accept a car that had rarely been back to bmw. My local dealer insists on full BMW history - though I'm hoping to make the 5k before my next oil inspecion last until after April when the warranty runs out, I can live without paying 220 quid for an oil change.
One question though; why on earth did you buy a car from a main dealer if you intend to sell it soon? The depreciation will be huge being as you'll have paid way above market value for the car to begin with (My current car, an 03 320d was from a main dealer, I've resolved to keep it at least another 18 months because I can't live with taking it back to them knowing I'll have lost about 4k)