My question involves towing laws for the State of: Washington

Our apartment complex towed our vehicle because they said it was "leaking oil". A man from another apartment had parked his vehicle in this spot for months! It leaked A LOT of oil and went into the storm drain. I know they eventually threatened to tow him. Our vehicle did not leak oil there. We have an old pickup truck that was recently given to us by my fiance's father. It has brand new tabs on it, only a month old. He was driving it daily for awhile, then decided to drive his Honda to save on gas since his new job site is an hour from home. In our lease it says:

"Parking of vehicles on lawns, gardens or sidewalks is forbidden. Vehicles may not be repaired on the property except those repairs which take less than 8 hours to complete. Inoperable vehicles or vehicles with flat tires shall be towed away at the vehicle owners expense."

The vehicle was not "inoperable" we drove it home from the tow yard. The next day we took it out to my fathers house, to prevent this from happening again. The only signs that are up around the complex are signs that are in front of the fire lanes that simply say "No Parking" there is no tow company information or phone numbers posted anywhere. She had put a sticker on the window on 1/21 it said "your vehicle is leaking oil, call the office at 555-5555"... that was friday evening, we had left to go out to my father's Friday and did not return until Sunday night. We didn't see the sticker until Monday evening, when the office was closed. After my fiance came home and saw it was gone we went to the office and found out what happened. When we got the vehicle back there was another sticker on it that was put on that day 1/25 that said "your vehicle is leaking oil and will be towed 1/25 at 9:15" so she put it on and towed it an hour later.

Frustrated because we are very financially responsible students, but very poor we had to put the towing expense on our credit card to get the truck back. Now to file a "wrongful towing" claim its going to be $75... Do I have a case?
I took pictures of the outside showing no towing signs, only the fire lane "No Parking"
We didn't think to take pictures of the stickers before we removed them... :-/
I called the towing company they didn't take pictures of the vehicle before they towed it to show any violation or record of notification on it.

Should I pursue this or will I lose more money?
Do I have a case?