First of all, it depends on how the contract is agreed (if you don't have a contract, then this won't work); Secondly, Shi Sheng Company said that you broke the contract and asked them to produce evidence. If there is no evidence that you broke the contract, there is no legal basis for them to tow the car privately.
Thirdly, generally speaking, the car loan company needs to make a dunning on the repayment date, which reminds you that it is time to repay. If they don't remind you, you can bite the bullet and ask them why they don't remind you of the repayment. It's their fault. Besides, as far as I know, late payment only requires late payment fees, and their demands are really unreasonable; Finally, even if there is a provision in his contract, you can go to court to sue them, because this provision was made under obviously unfair circumstances.
There are relevant breach clauses in the performance of the contract, and the car will not drive away after one day's overdue, so it can only be enforced by the court. It is said that banks have no right to move their own cars. Because the vehicle ownership relationship is shared by the lender and the bank, and the bank also has mortgage and guarantee, it needs to be prosecuted by the court and enforced by the court.