Thanks for posting the detailed photos Laurens, very interesting. It appears to be a good job and the upper tube inserts go further past the crack prone area around the upper rear wishbone mount than I had thought possible. It's much easier to see exactly what the situation is with the body off, I wasn't sure exactly where the tubes were crimped. The welded in brace should improve things greatly as well.
Nice to know that there is a viable alternative to the full, expensive MMC chassis change and at a more reasonable price as well I assume? I had wondered if a whole new forward chassis grafted on, as with Trikings, would be a better solution but that looks pretty good and should sort the problem for good.
@Planenut—Yes, M3W Services has a 'secret' trick to reinforce the upper rear tube. I'm not allowed to tell you much more. You better ask them. While not low, the price for this upgrade is significantly less than that of a new chassis at MMC, including labour, which is approximately less than half the MMC's cost, making it a much more affordable option.
@Bunny —The driving experience is much improved, but that could also be because M3W Services upgraded the rubber mounting for the engine (see my post about the mirrors).