There is a way to check and make sure those new wheels fit before hand. You would have to remove a wheel. The front works best in this situation, so that you can verify turning clearance at the same time. You would have to know the offset, diameter and width of the wheel your wanting. You would also measure out the diameter of the wheel from the hub center. Wheels are technically a inch wider than listed and a inch more in diameter. The wheel measurements are taken from the inner lip and not the outer edge of the lip.

Example: 18x7 wheel with a 38mm offset. The wheel is really 19x8 in size. Offset is measured from the true center of the wheel. Backspacing is measured from the back of the wheel to the mounting plate. The width is 203mm (8 inches divided by .0394mm) divided by two is 101.5mm (4 inches), that's the center of the wheel. Now subtract 38mm (1.5 inches) and that would give you 63.5mm (2.5 inches). The wheel would set 63.5mm (2.5 inches) forward of the mounting plate and 139.5mm (5.5 inches) behind the mounting plate. Now just measure out 9.5 inches for a radius. Using a T-square works good for all the measuring or take a piece of cardboard. Cut it the width of the wheel and diameter. Cut out the middle so that you can place it on the mounting plate as if it was the wheel with it's offset. Turn the steering wheel around to check thing out. Rememember to leave room for shock/coil travel.