Leased Vehicles for Employees

We are using Oracle's Vehicle Repository and Vehicle Allocation modules to track our leased vehicles.  We have several lease-related fields, such as lease duration (in both miles & months), total lease price, monthly lease price (which could easily be derived based on total lease price and lease duration), and the cost for exceeding the lease terms (based on mileage) that do not have an obvious "home" in the Vehicle Repository.  How are others tracking these values in their organizations?

Thanks,
Tommy C.