Listen, fact of the matter is, if u have 235mm wide tyres on, and the car is on super lows, believe me it will rub in the guards. My mate has a VR with 17" matrix wheels and super lows, standard shocks, his car used to rub on a lot of bumps, and when there was a few passengers in the ass end it was even worse!
He got his 2 rear guards rolled at the tyre factory for $70 a guard and the problem is fixed, never again has he rubbed. As for seeing if they've been rolled or not, you can check by looking at the lip of the guard and seeing if it is rolled back further than normal, even by comparing it to the 2 front guards. Also one thing to look for is cracked paint in that area because its a common thing to crack the paint if the guard rolling job is rushed...