No, you can apply to borrow the full amount you need to purchase the vehicle, as well as any related costs such as on-road costs or insurance, if you wish.
Consider only borrowing what you need, as if you’ve managed to save some money toward the cost of purchasing a vehicle, this could mean you need to borrow less. And the less you borrow, the sooner you can pay off the loan and the less interest you’ll need to pay.