New Hengst air filter would not fit my BMW

Expect to pay more for the K&N initially but they pay for themselves after a couple of swaps.
The way I look at it, if your driving environment is clean enough to allow the use of a low efficiency air filter, you would only have to change a paper air filter every 100k+ km anyway. So it would take a very long time to see a financial payback.

On the other hand, if your driving environment is dusty enough that a paper filter would need to be changed, say, every 20k km, a low efficiency filter could result in significantly higher engine wear. The K&N filter would pay for itself quickly in this case, but it wouldn't be worth the increased wear.

If the driving environment is not dusty, but the filter clogs quickly due to large debris getting crammed into the pleats, a K&N might make more sense. This is what happens with the filter in my car. My solution was to install insect screening over the intake to prevent the big stuff from getting to the filter. Previously, it got pretty clogged up in 30k km. With the screen, I expect that I can easily double or triple this interval.
I ordered a Mahle filter from ECS today, since that is what is currently in the car (should have checked before ordering the Hengst). If the Mahle fits, I'm sending the Hengst back. If it doesn't fit, I will have to figure out if I'm doing something wrong.

Also, I could have gotten a new filter from the BMW dealer today, but it was $89 incl. tax. The Mahle from ECS is $60 incl. tax. (free shipping).
I got the new Mahle filter from ECS today. It is made in France, FWIW. Will try to install tomorrow; too tired to mess with it tonight. Here's a couple of pics. The black on the upper left of the filter seems to be glue or ink, not sure. Not grease.
Shame about the Hengst. I almost use Mahle exclusively now for filters after various bad experiences.
Shame about the Hengst. I almost use Mahle exclusively now for filters after various bad experiences.
I have no ill will toward Hengst but I won't buy anything else from them for either of my BMWs. Not worth the risk/hassle. I'll be using Mahle exclusively now unless they give me a reason not to.
Last update: Returned the non-fitting Hengst to ECS for a refund. That sucker cost $10 to ship via USPS, and ECS wanted >$20 for a pre-paid return shipping label. I guess it was expensive to ship because of size, because it wasn't heavy at all.