Violations can happen innocently and given the complications of driving in unfamiliar conditions, and the ubiquitous deployment of speed and other monitoring cameras, chances are you won't even be aware of your transgression when it happens.
If you're driving a hire car, your first indication might be a charge against your credit card, imposed by your car hire operator, along with a fat administration fee for the inconvenience of paying the fine on your behalf.
If you cop a parking ticket or on-the-spot speeding ticket and choose not to pay, the authorities might again eventually submit the penalty to your hire operator, along with any late-payment fees that apply.
If the car belongs to a friend or relative, the fine will be issued to them and they'll likely be pursued for payment, not you.
Unless the authorities have access to your credit card details, in most cases you can get away without paying, and won't be chased, but if you return to that country and are pulled over by the constabulary, things could get awkward.