I just moved from Scotland to Nigeria and though the people here are wonderful to maintain a car is a big problem as the garages seem not to understand how to fix a bmw. My model is the 535 and the symptoms include intermittent cuts in fuel flow resulting sometimes in loud backfire. The fuel pump was suggested as the problem and after changing the fuel pump twice, still no joy. It such a sweet car to drive in a country where petrol is relatively cheap and I will hate to replace it. Any solutions?