storage fees

What is the name of your state? California
Verbal agreement to purchase a car between 2 friends of mine, me being the middle person. seller allows car to be towed from her property to buyers mother in laws property. The title of car could not be found after 1 1/2 months but now have one. In the meantime, mother in law now says she is charging for storage costs of vehicle. No payments have ever been paid from buyer. My question: Can mother in law collect storage fees?

Not unless it was stipulated first, or at some point since the car was put there. She can't demand payment for something that was not agreed upon by the parties, or at least by notification. If she told you or the other party that on (or, "as of") xxxxxx date storage charges of $X will be charged, then she has a right to collect from that date until the car is removed. However, if there is nothing in writing she'd have a hard time getting a judge to agree.