How long does a car company have to charge you for excessive wear and tear after you turn vehicle in

I assume that the obligation to pay excess wear and tear is set forth in your contract.  Assuming that (a) there is no time set forth in the contract for the car company to demand payment; and (b) that the car company has never expressly waived the right to collect excess wear and tear, i.e. by telling you that you didn't have to pay it or that nothign was owed, the question is whether the car co. has waived its contractual right to charge you for excess wear and tear by delaying 4.5 months to make its demand.  There is no set time for a waiver to occur by silence, rather it depends on the circumstances of each case, I think it very unlikely that a court would find that the car co. waived it's right by delaying 4.5 months., it's just not a very long period of time.