I doubt they’ll let you hand it back before the garage has even looked at it.
Are you sure the car doesn’t have a problem? Ask the garage to assess it maybe? What do the forums say, is it a common feature of the car?? Best of luck trying to sell the idea that a car is ‘dangerous to drive’!
Yes, it is a known problem with this vehicle. Many other owners of the same model are also complaining about the same problem and how dangerous it is. I have found a way around the problem which is to disable the stop/start system or to use the sport mode and there is then no lag. I suppose I can live with this because apart from this problem it is a lovely car.