I've had this 2017 Lincoln MKZ for about two years and never had any issues until last month when a really sharp vinegar smell started coming out of the vents right when I turn the AC on. It goes away after a few minutes but honestly it's embarrassing when I have passengers, and I'm worried there might be mold or bacteria growing in the evaporator case. I tried one of those DIY foam cleaners through the drain tube but the smell came back after a week. A buddy told me to Click Here for some detailed info on how these Lincolns have a common problem with the cabin air filter housing not sealing properly, letting in moisture. Before I spend money on a full evaporator cleaning, has anyone successfully fixed this smell on their MKZ or Continental? I really don't want to keep breathing that stuff in every morning.