If this is on a PCP then you have to stick to the terms of the contract. Normally this will be deposit, followed by monthly payments, followed by a 'Minimum Guaranteed Future Value' at the end of the term. That's where it can get messy. If the MGFV is less than the market value of the car then you still have some equity in the car to use as the deposit for another PCP with the same dealer. Or you can buy the car for the MGFV and try to sell it yourself for more, giving you equity to use as a deposit on any other finance deal with any other dealer.

Hyundai normally sets MGFVs at less than the expected market value at the end of the term. But what can happen with some other makes is that the MGFV is more than the market value of the car, in which case the dealer might offer you a deposit contribution for a subsequent PCP instead of a discount on the new car.