I created the same sometime in December 2013. I used 2 tables, 1 for Vehicle/Equipment List and the other table is vehicle/Equipment History.
What is recorded in the Vehicle table are the description of Vehicles, bodyno, serial, plateno, type, model, date acquired, purchase amount, and assignemnt/location.
In the history record are the, records of Preventive Maintenance/Corrective/Repair Details, Materials/Items Used, Cost, Date, Reference Code/Service Report, Remarks, Other info such as Back job. And has a recommendation. That concept was gathered from ISO procedures for Preventive Maintenance and Repair. that is to completely monitor, control and suggest if the service vehicle is for salvage value or for maintenance and will determine if the cost of maintenance vs the cost of new equipment for replacement and can justify status of every equipment/vehicle.