Hello! I can recommend you to rent a car from Thessaloniki Transfers. At https://thessaloniki-transfers.com/our-fleet/ you can find the vehicles they have to offer. I often rent cars here when I travel in Greece. Their cars are always very clean and the staff is nice. You won't have much trouble to rent a car. They also offer a wide range of quality services such as airport transfers, hourly rentals with a driver, car rentals and more.