I'm very interested in your bulkheads, but have a few questions/suggestions.
I REALLY like the idea of moving the motor inboard and had been curious why Associated had not done this on the car...in fact they went to additional effort/expense NOT to. I'm guessing you run the pinion "backward" like on off-road cars? Any chance of getting a pic with a motor installed in your demo without the top plate installed and with the top plate installed so we can get the flavor of what we're facing?
At first I'd wondered "why not just get the left side plate" until I looked more carefully and saw that the layshaft bearings are now carried directly in the bulkhead and a fair bit lower than standard. So much for that thought
It looks like the layshaft is carried about 3-ish mm lower (like the Exotek carriers X2)? This, obviously, cuts spur clearance on larger sizes (and my not really be relevant anyway depending)...any idea what the largest spur size that will fit with your mods?
How is belt tension affected by carrying the layshaft lower? Exotek claims a modest reduction in tension and would imagine that tension would be further reduced if you're parts are carrying it directly lower than it's current position.
I can see you've milled the chassis on the inboard side under the motor--is that done to the same depth as the standard AE milling on the outer "tab" of the chassis or have you taken both down thinner?
I must confess to not being wild about not having the "leg" in the bulkhead ahead of the motor to screw down to the chassis. I can see on your mule that at one point you must have because the chassis has been drilled where the new screw would go to pick up this leg. Correct me if I'm mistaken, but my guess is the leg was eliminated to users wouldn't have to locate, drill and countersink a hole (whose location is critical to proper fit) in their chassis. All the other screws appear to be as-located by AE. I would offer that if you made a paper template from your "mule" chassis shown that identified where the screw would live that customers could hit this easily enough. OR...I'd bet you could pick up chassis plates at dealer cost somewhere, drill and countersink them, and offer them as an extra cost option for users who lack the confidence to do that drilling.
I can imagine that the top plate provides enough bridge to keep longitudinal flex under control without this leg, but I am not at all crazy about the mass of the motor being so unsupported. It is hanging clear out ahead of the screws. My concern would be that in a hard side impact the mass of the motor could pretty easily bend the bulkhead, inertia being what it is. I've seen similar thickness 1/12 bulkheads bent due to the motor mass and they're supported all the way around and fairly close to the motor.
If you guys were to go back to (and I'm certain it was there at least at some point in development) the forward leg ahead of the motor I'd be ALL over these bulkheads, as it is I have substantial concern on this point. You'd still be "losing" the rear foot from the original AE motor mount, I just think too big a bite has been taken by eliminating that front foot.
I look forward to your responses. I think you guys are just THIS close to having a great product that I wouldn't hesitate to purchase.