I would think that renowned shops that specialize in this sort of thing would know more than the average Joe. What do you have to support your statement? I know for a fact if you are going to machine a wheel to change the offset it can and will damage the integrity, no questions. The wheels are built to specific sizes/weights and if these are changed then the wheel will not be what it was from when it left the assembly line. OP could go to a wheel shop and they could just say it can be done and later down the road the wheel will be split in half. World isn't perfect so you shouldn't be believing what everyone tells you.
FYI, you cannot roll the fenders on our cars.
Originally Posted by m3an
OP there is nothing wrong w/ a competent shop removing a few mm (dependent on available room on hub) to decrease offset, don't listen to all the negatives here. Ask the wheel shop as they'll be the ones doing it. If it were me, I would try and roll the rear fenders slightly first. Cheaper and you're not messing w/ the wheels at all. Remember, ask the wheel shop as this method will vary dependent upon wheel