You'd need a table with vehicle data (e.g. tblVehicles). When you get new year/model values you simply add new records. Same for Customers. Then you need what's known as a junction table. This table ought to have a PK field (autonumber will do) such as CustRequestID as well as the PK values from Customer and the PK values from Vehicles. Those values are known as foreign keys (FK's). This is basic normalization, which is probably something that you really should research otherwise you might be in for a rough ride.
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.