Hi;
    From memory i think there isnt much difference between the two cars,
mainly cosmetics and such, but to actually swap them over is a matter of
unbolting and re bolting on to each car. I think, the 2 base cars were in
groups, ie  XT and the XR, XY and XW then the XA, XB and XC were just about
interchangeable. XD, XE and XF are in the same seat. So hope i helped.

Peter