Traveling to Costa Rica (flying into San Jose) with four people including a 9 year old and 70 year old in 13 days! We have booked hotel rooms in the Arenal area for nights 4, 5 and 6, but don't have firm plans for the first 3 days or the last 3 days. My thought was to visit either the Manuel Antonio area or the Guanacaste region for the first 3 days, but don't know what to do for the final 3 days of our trip. We will have a rental car. Any trip suggestions or advise would be appreciated.