Question about association and parking.?

I own a townhouse and I have association. Due to the lost of my job a year ago, I couldnt pay my mortgage and assoc fees. Right now I'm dealing with my bank doing a modification so i'm still leaving in my townhouse. I owed money to the association, and I'm wating for my modification approval to see what can I do to pay my assoc balance due which is around $4000. Today, I just received a letter from the assoc company telling all the owners that on July 31 all the cars must have a sticker. And they send a form asking for car info, driver license and registration copies but also it says that all the owners that have a balance due will not received the parking sticker and cars will be towed. Is this legal? I mean when I bought my house I paid for the parking too because I have 2 private parking space in front of my house. It is a townhouse no a condominium. So It is ridiculous that I need a parking sticker to park my car in front of my house. Can they towed my car anyway if dont have that sticker because I owed them money? Thanks!