The transmission filter uses data from our partner sources (Cars.com, eBay, CarsDirect, etc.), which they get from the dealerships and private sellers listing the cars. As far as I know the filtering is working properly on our end, but it’s possible the source data is wrong in some cases. It would really help if you could let us know the exact search that’s bringing up bad results, as well as the vehicles (or at least some examples) that are showing up when they shouldn’t. Then we can contact the relevant partners to get them fixed. Thanks!