I'm only guessing here, but I would say the injectors currently in your car are the original ones? The original injectors are made of steel, and are prone to corrosion over time. The new style injectors are made of brass, so corrosion is not a problem. You can buy new injectors for around $25 or $30 each, if you shop around. Try and cross reference your injector part number to another make of car, like a Mercedes or even a VW. As for changing the injectors, it's not a terribly hard job if you have some mechanical ability. You will need to buy some o-rings too. I'm not very familiar with the fuel system on the 308, hopefully someone with actual 308 experience pops in to help.