Parking and speeding fines are part of driving in Dubai. You won't get pulled over, but you may well get flashed by one of the many speed cameras, or a ticket may appear on your car window should you not pay for parking. With speeding fines usually 600 AED and parking fines at 200 AED, these can accumulate rather quickly.
Most drivers don't pay the fines immediately, preferring to wait until it's absolutely necessary when their vehicle registration is ready for renewal. This can result in a hefty pay out when total fines for the year are added up.
A discussion thread on Reddit yesterday about how much on average people accumulate had some interesting answers!