The missing welds were in the Supra, assembled by BMW and in a place that you can’t get to after the car is built. Thus, you scrap them. It’s easy to “say” just go into the body shop… it’s another to actually do it to an internal weld with no access without cutting out a (later) welded frame member and then trying to weld it into back the correct position. Yeah, scrap the cars, or, make then un-drivable forever and put them in a museum. They were low mileage Mark Vs. A shame, but they caught it pretty quickly.
More force on the clamping bolt or nut isn’t necessarily the solution. A given material bolt or stud of a given diameter will only have a plastic zone that goes so far, depending upon the hardening applied… torque beyond that and the bolt/stud is permanently deformed and usually weaker and likely to snap or gall (and be unremovable).
This isn’t rocket science for the design necessary.
The AWD version has supposedly less torque applied by the smaller electric motor than the FWD version (except in the RZ450e).
One other difference will be the shifting front/rear bias of the AWD logic, if that has much effect.
I’ll wager that the “mistake” were incorrectly machined/drilled hubs or wheels, with resulting precession characteristics, made worse by the more direct drive of an electric motor than by an ICE with some “slop” in the transmission and differential(s) (which soak up some of the impulse of the ICE cylinder firing).
Toyota and Subaru are quite motivated and qualified to engineer and implement a robust solution to this problem.
We (owners, potential owners, shoppers and kibitzers) are an impatient bunch.
I especially feel some compassion for the owners who have their cars parked (at a dealer or in their garage) and are unable to use them, while the traction battery and tires age on their new purchase (and payments are due, clocks are running on the provided radio and software feature subscriptions).
The rest of us will just have to suck it up.
(here I am personally waiting for SoA to accept new Solterra orders (mine) and am quite looking forward to the vehicle and not at all worried about this issue for the long-term).