motor vehicle registration in PV

I am thinking of going to PV to buy a car. Does anyone know the name and address of the "hacienda" where I can check for outstanding debts/fines and past plate fees? I tried google with no luck.
Is there a tax to be paid?

The place were you register the vehicle is on Av Grandes Lagos and Carlos J Barrios. I am not sure if this is the place you need.

It is called UNIRSE.

I am not sure of the address, but it is on the south side of the rio pitillal.