Just thought I share this with you all... just changed my microfilter because the a/c ws still churning out mucky smell after I went in for a DWD2 service (useless). Anyhow, the new microfilter was great! About 30-40% more air, definitely fresher, but I regret not cleaning out the chamber holding that filter (was rushed by gf) enough. But overall satisfaction very high. $45 for original BMW micro filter & about 1 hour well spent. Highly recommend!