Coil pack under the transmission? Shome mishtake there I think, it sits to the right of the cylinder head and has 4 plug leads coming off it. Coil packs do give problems on other models but not as much on yours for some reason, easy way to check is take it off, turn the coil pack over and see if there's any signs of burning/blackening. As said mate these are more prone to fuel supply problems, the pump and also the module that control it under the rear seat need to be tested.