My dealer is multi franchise & tells me MG cars are usually pretty trouble free. It's rare to get issues. He sells a lot of cars including MG & I know the dealer very well as I've bought cars from them for years. The one criticism they make of MG is they are sometimes poor communicators & a bit slow to act on warranty claims. But they usually get there in the end. They also said that's pretty much inline with many other brands they sell.
Regarding MG, I know others who have bought new MG cars, none of whom have any issues with them. My own car is now near 3 mths old with just 1500 miles on the clock. Aside from a minor paint issue to the bonnet which is being assessed by MG, the car is faultless. In fact it's had zero operational niggles, unlike many of my previous new petrol or diesel cars from various big brands.