At the tow yard I'm associated with, we have the police come out to fingerprint cars at least once a month. These are usually stolen recovery vehicles or a vehicle used in a felony of some sort, but the point I'm trying to make, is that they fingerprint vehicles all the time.
Now if they will in your case, who knows? If they have the time and your ex pushes them, they probably will.
However, even if they identify your prints, this alone may not prove you were the one who vandalized the vehicle, but it might make you the number one suspect and helps to build a case against you.
Time to grow up and look to the future, rather than holding that anger inside and dwelling on the past,,,