Convenient Barcelona car rental to Costa Brava

You might try Google maps -
https://www.google.com/maps/search/rental+cars+near+Barcelona+Spain/@41.3661408,2.0549386,12z/data=!3m1!4b1?entry=ttu

Verify Google's info with the local rental office before making the trip to the office.

I discovered Ganxo Rent-A-Car while looking for a deal on car rentals on the Costa Brava last summer. They turned out to not only have great rates— at no extra charge they will bring the car to your hotel or accommodation and also come pick it up when you’re done with the vehicle. They list 30 towns and locations they will deliver the car to and pick it up including Barcelona’s Aiirport, Begur, Palafrugell, Tamariu, Girona, Tossa de Mar, Lloret de Mar and many other towns. No charge for extra drivers, no hidden charges, no nonsense. Starting at about €50 per day, you can rent a small car including the valet service and Ganxo covered ALL the insurance for a daily price of about €10. Economy cars, large cars and vans are also available to rent. The minimum age to rent is 24 with 3 years of driving experience required.
Ganxo took all the stress out of renting a car in Spain for a great price and the valet service was the icing on the cake. It was almost too good to believe.
There are Express buses from Barcelona’s airport and Barcelona’s northern bus station (“Barcelona Nord”) to Lloret de Mar in 75 minutes and Tossa de Mar in 90 minutes and Rodalies trains— the commuter trains— go to Girona and other destinations so you don’t really need a car to reach the Costa Brava where a car does come in handy.
An International Driver’s Permit (IDP) is legally required in Spain and you can get yours with the photo included at your local American Automobile Association (AAA) office for $30
www.GanxoRent.com