If the canvas top doesn't fit properly, GENTLY warm the resin with an hair dryer in order to get a snug fit.
Here's an inbox review and an out-of-the-box construction of the Italeri offering:
(click to open in new tab)
A picture to help you use the Kubelwagen conversion:
Quick post just to link some photos showing the connection between the axles and the wheels.
2012 IPMS Belgium "Plastic and Steel"
FBMinis/Italeri Kubelwagen by Rob Haelterman