Big dirt parking lot close to the Malecón. Since we arrived on a Sunday afternoon, we paid $50mxp. Town was packed. Lots going on. Music was going until about 10pm then it quieted down. Cops knocked on our window at midnight to see what was going on with the parked van but they said it was fine to park here overnight. Public banos on the south side of the lot but not open after 7pm. I would expect it to be much quieter and to not have to pay during the week.
Place: Chapala public parking
Location: 20.28686, -103.18751