Eventhough you reach Sóller by train and bus, it is hard to do without a rental car. If you want to see more of the island like the spacious beaches in the east, the wine regions around Binisalem or maybe Palma with its vivid flair, shopping possibilities and nightlife, you need a rental car to get around.
You can take into consideration renting a car outside of Sóller if you need it during the entire stay on the island. You can pick it up and leave the car at the airport if necessary although this service in particular is offered by Sóller based car rentals as well.
Car rentals are favourable on the island. Especially at the off peak season you will find that the car rentals underprice themselves with special offers, meaning you´ll find a car for under 20€ a day. During the summertime you´re advised to book in advance because many suppliers are fully booked.