I had exactly the same problem when bought my 07 HR a few months ago. I couldnt live with it so took it back to the dealer. In my case they diagnosed the fuel dampers as the fault. There is a fuel damper on each fuel rail. We got some from the US on Ebay, I think they were about 25 USD each and dont take long to install. Mine runs really smooth at low speeds now. It's a lot more enjoyable to drive Dont accept the problem. Give the dampers a go