The button I push to adjust the temp up and down broke off and would like to know of where to purchase parts to fix. I'm concerned if I take it to the BMW auth. shop they will want to replace the entire panel, which will be expensive.

go to the dealer and ask for the climate control panel buttons only. next time also dont be "concerned" you know you dont have to buy what they are selling.

+1 a set of buttons is available separately for about $20-30 bucks I think. It's the whole front panel with all the buttons. Just pop out the button you need with a pocket screwdriver, and pop it into your panel.

Thanks for the help. Good point re: being concerned.