Tell the dealer you will buy the

Car right away if the dealer accepts your offer 52,000. If the dealer does not accept your offer, you leave immediately, but leave your cell phone number to the sales adviser and told them to call you in one or two days if they change mind. Do not negotiate with the dealer at this moment unless they accept your offer. You've got to let them know you need to buy right now and you like Benz but you stand with your offer.
I am pretty sure you will get this car with 52,000 or 52,500