[slotloco]

Nice review as usual Brian

Just a couple of points - Firstly, if your rear track IS 2mm narrower, it is simply the setting of the wheels on the axles.
I have done a fair bit of prep on these, to add them to the race roster of our DTM Classic National invitational race event next month.
With the wheels set just inside the rear arches so they are not visible from above, and rocking/tilting inside the arches when you have body roll/lean, these, the Mercedes, and indeed the CA45 Alfa and the Opel all come out at 58mm and change to outside width of the 10mm N series tyres.
So for anyone who worries that a narrow rear track will handicap it - don't. 

Like you, I was surprised at how they perform. Seeing the higher chassis, and not being able to make use of the "sliders" since we run our cars on wood tracks, where they always perform best with 4 wheels planted, and no "tilt" in the front axle, I expected them to be less stable than the existing models.

They have run against more than the BMW in 1990 at Macau in 1991 where they ran against BMWs'  Mercs, and the odd Sierra.
For the 1991 race, they were invited back, but put on a "good behaviour bond" in the form of 140kg of weight penalty.
That sorted them out.... :) 

So while there were 2 sets of rules in play in the race - Group A and DTM, - the weight penalty brought the field much closer together, and this history adds a bit more relevance for the purists, to be putting these on the track with the other Slot.it DTM cars, and indeed those of Fly, Ninco and Scalextric.
Macau 1991

And of course, they were running against a pretty wide field of Group A rules cars at Bathurst, with the winning car from 1992 due out this year. 
It was ruled winner on count-back despite crashing immediately before the red flag, much to the Dick Johnson Shell Sierra awarded 2nd place.
The Bathurst fields also included the BMW

The CA47c car, is from Spa 1990. The Nissan ran there 1990 - 1992. 

Bottom line for me is, as you say, a lovely model that no maker has done previously, and performance puts it squarely in the mix with the intended running mates from Reggio Emelia.