Lets talk fitment
 

Hi guys I was wondering what the most aggressive offset I could put in a Boxster with a 17/18x9 would be.

I plan on running a 17x9 or 18x9 square setup. Do any of you guys know if I can go as low as a 25 offset without rolling/pulling the fenders?

I'd like to put some wide tires on them, and I prefer the lower offset since I prefer the wider track

That depends on how low your car is and how much neg. camber. I have run 17x8.5 wheels with 255 tires up front, stock suspension and no rubbing issues. Other Spec guys run 255s with a 5mm spacer, lowered car and more aggressive camber. one guy runs really low with 285s all around, fenders seriously rolled and still a bit of fender rub at full lock.