Petaluma offers 2 hours of free parking in the downtown,
and 2 free parking garages:
Keller Street Garage is located on Keller Street between Western & Washington. 
The bottom level parking is 4 hour and the higher levels increase from there.
The Second Street Garage entrance is located on C Street between
First and Second Streets.  It's all day parking on every level.

There are no parking restrictions just a few blocks out of the downtown
in any direction. Think of it as your pre and post dining workout
to park and walk in and out of the downtown.
Have a great day and be careful not to get a parking ticket.