Was working with a dealer on a 330i 2017 (new with 28 miles on it) and had two promo codes (X2 drive and Ski Moritz). The dealership refused to apply those stating that they could not be stacked with loyalty even though the fine print says nothing of that sort. I still went ahead and signed the lease since the deal was a killer ($238 per month on 330i MSRP $50750 with $500 down).
Can BMW NA apply the promo codes (either one) after the fact? If so, what would be the best way of getting them applied or getting a check back?
How long ago did you sign the deal? If the deal hasn’t funded yet you can just redo the contract if you’ve now obtained proof they can be stacked. If the deal has already funded, then that sounds incredible difficult to unwind.
Usually those codes do have exclusions and also require 50% dealer participation. You can certainly ask, but you made the right choice my signing anyway - that’s a great deal on a 330i.
You should post in the Trophy thread.
I definitely will 
If only BMW would send a check for $1000 that would make this a lot more sweeter. The lease got funded this morning so my only option I think is to talk to BMW FS…
The OL code requires dealer participation as @28firefighter has said. It’s 500 from BMW and 500 from the dealer. The dealer can refuse to participate in OL codes (you should see “Only valid at participating dealers” in the fine print), however. Or, I’ve seen them pass along the 500 from BMW and not contribute the 500 on their side.
I wouldn’t hold my breath, at this point though, on getting this applied, however, you may get lucky. Good deal regardless.
If only BMW would send a check for $1000 that would make this a lot more sweeter. The lease got funded this morning so my only option I think is to talk to BMW FS…