Fotoradar and non-EU car, how to pay fines?

I drive a car with non-EU plates. A year ago I was driving a bit too fast and a fotoradar flashed at my car. I am fully willing to pay the fine, but I never received any bill for a fine, which is not surprising because as far as I understand Poland has no access to information about non-EU cars. Therefore I don't know how much I owe or how to make payment. I forgot all about it and figured I don't need to worry.

But recently I heard a rumour that the Straż Graniczna may in the near future gain access to databases about non-EU cars and deny entry/exit to their owners until fines are paid. I wouldn't want to miss a flight because of some old fine I was never even notified of. What should I do?

I also heard that in certain situations an unpaid fine can be grounds for imprisonment. Surely that doesn't apply to people who never even got a notification in the mail that they need to pay a fine right?

@Einstein

Just sell the car or change your registration number, all will be well

@dolnoslask I'm not planning on selling it for at least another year. Who sells their car because of a fotoradar??

I did after setting off almost every fotoradar in France when I was late for a ferry lol

@Einstein
BTW,is your car legally in Poland?Did you ever get the extension response from Uzad Celny?In fact all depends on that too.If its legally in Poland and if you have a resident card or meldunek then its there fault,they could have informed you.If not,when you ever take your car out of the EU,you will be bombed with almost 75% of the cost of the car when imported plus the traffic fines with penalty and interest or after 2 to 4 years they will be looking for you.

It is best not to pay at all.