heres the measurement sof a nissan. looks like it's bout 1" wider than a xj. which wouldn't be too big of problem to deal with.
Not sure of the brand on mine, but this is the one I measured for you at a little over 62".
This is a Nate's Slim Line, I have sold the Jeep so I can't get the measurment from it, but you can see how it hangs out a little on each side.
Feel free to make our next ride, I might need to be pulled again, and a picture of a Nissan doing it would be really funny. ;D