Don't know much about the differences in the rear susp of a cossie and an Merkur XR4ti, but I run 245/45/16's on all four corners of my XR. I have front coilovers and 300# springs, and "sport" springs in the back that are -25mm below stock ride height... if that helps? I had to roll the fenders and do some minor "adjusting" to some of the inner fender well with a hammer, but it looks fine and once painted is unnoticable.

As for the scrubbing on the above pics, maybe use a spacer and roll the fenders?