Phaeton W12 on -> 6 cylinders?

Hi, is there the possibility to upgrade a W12 relatively cost-effectively so that I can castrate the W12 to 6 cylinders in urban traffic? Currently I also think about a gas system. Does someone have experience with the 12-er 2008 and gas? (Have read a lot already but it’s best for me to learn from first hand) (costs with car-becker?)