New boxster horror story

[mangoman]

Hi bought my first boxster a month ago, drove from guys house and engine overheated. Pulled in at service station, black smoke everywhere. Got it towed to specialist. They said the oil filter housing wasn't on the car and the radiator needed bled so got that done plus major service. The spark plug tubes were melted also so had those replaced. Picked car up from specialist and drove the car home, about 40 mile journey. When i arrived in my home town the car was misfiring, lost power and cut out. I was able to start it after it cut out and just got home. The specialist is being very helpful, he sent one of his mechanics out to fit a new coil pack to cylinder 6 where the misfire code was being displayed. When i took it for a drive it had made and improvement but still a loss of power through rev range. Also the code came back cylinder 6 misfire. There is also a slight water leak, I'm topping about 500ml of water after the 40 mile journey and about 100ml after 5 mile journey. No mayonnaise in oil cap.