new 06 m6 owner - questions

[rountree23]

i just bought a stock 2006 gto with 27000 miles and am wanting to put 18 x 8.5 rims with a 42 mm offset on it and run 245/40/r18s on them, my question is will they fit without having to roll my fenders?? also i have muffler deletes on it already and i am wondering if i can go get a resonator delete at any muffler shop. thanks in advance for all the advice