To be really honest I didn’t appreciate the engineering of the MF-1X that much. The trickiest part is the assembly of the rear gearbox.
Those tiny squares of rubber in the engine well make pretty difficult to align the two shells. The replacement of the steering servo, squeezed in the front gearbox, looks a real pain. I’m a frugal guy but there’re piles of gears to grease, the two small tubes you find in the kit are not enough. Back to the rear gearbox, a little window should help adjusting the gap between the engine end the diff gears. The engine gear is too far from the outside to understand how it matches to the diff one, especially when everything down there is greased.
As usual the chassis can be built in 3 sizes. The Beetle Rally is a L (239 mm) body whilst the Giulia drops on a M (225 mm) [in the real world the VW wheelbase was actually 50 mm longer than the Alfa’s].
To fit the body you can use the standard mounts and drill more holes or build a new strut. This was made of birch plywood, wood and spare mounts.
If you can do by yourself to fit the body on the chassis, you definitely need a shaft shorter than the 203 mm one included in the Beetle Rally box. The right one for the M lenght is 188 mm, catalogue part no. 54672, aluminium made.