Yeah, Its a new car thing though not just MG4's I ran the numbers on the new Renault 5 nigh on 30k for the spec I'd want and its worth 11k GFV after 14 years. Its now (the '4 has grown on me especially since I put Eco Contact 6's on the back) the sole reason why I am handing it back at the end of the PCP, I got a £16.5k GFV when I bought mine, I'm not making up that loss in refinancing.
I would say always look into return to invoice gap insurance if you are buying a car on PCP for the sake of a few hundred quid it could save you 1000's if the car is written off.