You don't know until you try. Some dealers will look askance, while others will see an opportunity to win you as a customer next time. While as a BMW franchise they are obligated to provide warranty service by BMW NA, one should not be surprised if they treat people who purchased their vehicle from them with extra perks, e.g., a dealer near me provides loaners to all their service customers, but only provide BMW loaners to people who bought their BMW from them -- others get Enterprise rental cars as loaners.