[WagonR]

Having spent some time on this, if you want a replacement key, I think this is the way to go:

1) Just get it from the dealer. The fob is programed by BMW, and as far as I know, only BMW. There's no way to buy a pre-owned fob and use it.

2) You probably just need to pay BMW for the physical fob and key, and not to pair it to the car. To be clear, you need to buy the fob and key from BMW so that the electronics for the key have you car's VIN in it. But, there's a step where you basically pair the key to the car. BMW likes to charge an hour of labor for this, but you likely don't need it.

On my '13 X3 with comfort access, I paid BMW about $375 for the key ($300 on the fob, $75 on the physical key part). They wanted another $125 to pair it. They'll call it program it, but it's really just pairing it. I declined paying for them to pair it (despite their warnings) and followed the online tutorials for pairing it, and it works perfect. Has memory for the second driver, comfort access works, etc.

On my '08 M3 I did the same thing, and I could pair the fob, but the profiles and comfort access didn't' work. So, it's not universal.

In talking with the dealership I've gone with this approach. Order the fob/key form them. Tell them I don't want it "programed" by them (they say programed, but it mostly means pair), because I'm just going to use it as a spare key to get into the car. They say that's fine, and if I want full access, I can always pay the same hour of labor to have it "programed."

In the end, you're basically only paying $375 vs. $500 for a stupid key, but I think on the f25, you don't need to pay the additional $125 to the dealer.