A number of different car rental companies operate at Treviso Canova Airport
Where can I rent a car?
Go to the car rental companies' offices located in the Arrivals hall on the ground floor of the airport terminal building.
IMPORTANT: You must report to the car rental companies' offices in the airport before picking up the car, even if you have already booked it.
Where can I pick up/drop off the car?
To pick up the car, turn left at the airport exit and walk along the covered pedestrian walkway to the parking area. After about 50 metres you will see "Rent a car" signs on your right.
To return the car, from the ring road take the second entrance to the airport on your left, follow the airport access road, turn right and follow the "Rent a car" signs.
Car rental companies
More info here about renting a car in Treviso Airport.