It says it’s a stretch but I really need to know if it will work with no problems
You have to give us some more information.. is the car lowered? if so, how much?
I run 18x8.5 ET35 on my GTI and I am lowered on h&r super sport springs. I needed to roll my front fenders and max the rear stock camber to fit them without rubbing.
If your car isn't lowered as much, should be okay, if its similar then i would either raise your car if you can, or buy different wheels.
Also depends on what tires.. i have 225/40/18 which is why it was rubbing, when I need new tires im going to go thinner and take off the rear camber.