Get them to reset everything again and maybe flush the fuel system inlcuding replacing the fuel filter, thats my only suggestion. To me it sounds like gear box and NOT engine. Like in an old Diahatsu Charage Auto under light acceleration you get the noise through the torque converter??

got the car tinted and the guy did the whole rear screen, he has done a few of my cars to date. I went with 3m darkest legal cause its a lease, I did have my eye on the 20% film though which I should have done for the rear due to the gay light coloured parcel shelf.