after I turn the interior air circulate on, I still can smell the outside air leaks in from A/C. anyone experienced it? how to fix it?

 

it takes a little for it to get the smell out from whatever is coming from outside. and it will just circulate that smell inside the car until you just get used to it and dont smell it anymore. i'm not sure you really have a problem

 

Usually on recirculate it will still allow o/s air to enter although a minimal amount 10%, or maybe 20%.

 

+1 No manufacturer will ever seal the cabin completely off from fresh air. You can imagine the issues with that.