How can someone be charged for drugs in car that don't belong to them

Importantly, yours is the wrong question.  How can you be charged is simple, the items were found in a vehicle which you were operating.  This is probable cause to believe they were yours.  The things you state as defenses are exactly that, defenses.  They do not preclude you from being charged.  A better question is can you be convicted based on those facts.  Without a full consultation it would be impossible to answer that.   The fact that they had a search warrant on your house is troubling to say the least.  You certainly have defenses as they are no doubt using a constructive possession theory for items in the car as no one physically possessed them.  Take the time to sit down with an attorney if you haven't already and properly prepare your defense so that it can be asserted at the right time.