The following cooperative government contracts typically cover vehicles and fleet including:

cars
trucks
utility vehicles
emergency vehicles
golf carts
vans
pickup trucks
golf carts
RVs
school buses
shuttle buses

Purchasing Cooperatives you can work with for Vehicles and Fleet: Cars, Trucks, and Utility Vehicles

Allied States Cooperative (ASC)

BuyBoard

HGACBuy

National Cooperative Purchasing Alliance (NCPA)

OMNIA Partners

Sourcewell

The Interlocal Purchasing System (TIPS)