The biggest thing is having the right offset. The width and offset will determine whether or or not you rub. Also remember to keep the overall diameter close to the stock size.

On 5th gens, 17's look good, 18's look great. Just depends on what you like. Just know that the bigger you go, the more goofy it's gonna look without a drop.

Personally, if you get 17s or bigger, you should lower the car to avoid the 4x4 look. It's an optical illusion really, but if you search on here, you'll see what I mean.