There are three unregistered vehicles parked in my townhome community what can be done? Two of the vehicles are parked in the guest spots in front of my unit so now if anyone in my building has a guest they have to park down the road Brigadoon

The property management, HOA or Security can have them towed.

Parking on private property is not handled by police. If your community has a HOA, notify them. Many communities contract with towing companies that will tow vehicles without prior notice. When you say those vehicles are unregistered? Do you mean the vehicle has no license plate? Police can respond to determine ownership and if the vehicle is reported stolen.