@Ryan ***
if the police stop you, there is no option to pay the fine, you can try to bribe the police to not hand you over to immigration but the police have no authority over your overstay meaning that if you do successfully bribe the police you will still be on overstay. Normally the police will hand you over to immigration you will then be fined but you won't be released until the fine is paid and you have a plane ticket out of the country. You will be taken from the IDC a few hours before your flight and escorted to the airport and then onto the plane and you will be banned from re-entering the country.
The best thing is not to be caught on overstay, if you make it to the airport without being caught you can pay your fine and leave possibly with a ban on re-entering depending on length of overstay, this is because being at the airport means that you do intend to leave, being caught anywhere else means you don't intend to leave and will almost definitely result in a stay at the IDC. I 1000% don't recommend a stay in the IDC I have done this and it is not a pleasant place.