Driving down the road, minding my own business, when....
I smelled Diesel fumes.... argh!!
(insert another comparison between Jeep and BMW)
Seriously the Cabin Air Filter should be made with activated carbon, not paper. I found a place that makes custom carbon filters:
The dimensions are 9.5" x 10.5" x 1.25"
Cost $125/6 pack, inc. Shipping. (which is about the same as the paper filters at Autozone)