They're not good vibrations

I TOOK delivery of a 2009 E-Gas Falcon G6 sedan in early March. I returned it after 1000km for a vibration problem, thinking it was probably wheel or tyre-related. When the dealer gave it back to me he said it drives ``beautiful'', but it was no better. Since then the car has been with the dealer 24 days, it's had a new tailshaft fitted and all the driveline mountings loosened and re-torqued. Again I was told it ``drives like a new one'', but again it was no different. Between 70 and 110km/h the whole vehicle vibrates and the dealer is now saying that all E-Gas vehicles have the same problem, even though a colleague of mine has one and it doesn't. I've now been waiting nearly two months for an NVH engineer to come and drive it. After 11,500km I hate driving the car, which is a real shame, because there is so much to like about it. It's the most comfortable car I've ever had and I have to say the paintwork is flawless, but it's just bloody awful to drive. If it's a recognised problem why is Ford continuing to sell the vehicle?