We just got back from Panama for Christmas, spending two days at the Westin Playa Bonita and two days at the Intercontinental.
We had no need for a car: the first two days, we did very little other than use Uber to get to the Westin and then hang out at the pool. The next two days we were in the city and, again, either walked or used Uber to get around.
We did do a tour of the canal locks and the old city, through My Friend Mario (not sure if links are permitted, but they're easy enough to find on Google). Great bargain: we signed up for a private tour, just the two of us, and got picked up at the Westin, did a driving tour, spent time at the Miraflores locks, did a walking tour of the old part of the city, had lunch, and then got dropped off at our second hotel. Our guide was hilarious, informative, and gave us great tips for our last day in Panama City.