To summarize, the chassis had not changed since the 4/4 Sports was introduced in 2008. Since around 2011, the Mazda transmission has been used, first in the 4/4 75th anniversary in 2011 and in the P4SS. As far as I know, these years still had the older BTR axle because Gönter Biener was able to change the rack and pinion in his P4SS. A little later, another BTR axle was used, which I have. There are no other crownwheel and pinion than the 1:3.7 available. Lost Simon explained some time ago that the diameter of the crownwheel was bigger and that MMC wanted not to invest in other than 1:3.7 ratios.
My question about the width of the rear has nothing to do with the choice of chassis, which has obviously not been changed since at least 2008. I am wondering whether the very late BTR axle that I have is slightly wider and therefore the rear fenders (on the same chassis) are cut wider, which I think is possible but I don't know for sure except by eye. Because my car looks more trapezoidal than the 4/4 with the old BTR axle until 2011 or so. Their look was more parallel from front to back. However, if that is the case, I cannot use the older BTR axle to change its ratio, which was used until around 2011 or 2012. I don't know for sure, which is why I started this thread.
