I ended up getting some M3 rear end bits, with a full set of basically every fastener for a E9x M3:
Diff housing cleaned up OK and looks beefy next to a large housing 335i diff.
Unfortunately one of the CV's is gone, so this project has been delayed and I'm now on the hunt for a RHS M3/1M rear axle.
In other news, I had the opportunity to vulture heaps of parts from a couple of E9x M3 wrecks and picked up various interior and exterior bits, carbon kevlar crash bars, any good front and rear liners, and basically anything else that was up for grabs and could help me bolt M3 body panels to a E92 non-M.
I've basically committed myself to bolting on a E92 M3 front end and side skirts, and running a hybrid M-Sport/M3 rear bumper setup with custom rear quarters. This means the car can have wider tyres allround and likely a lot less silly camber on the rear - less stance and more raceboi! While buying a better fitting set of wheels is the more sensible option, I love the Advans in this spec, I've always want to rock some bigboi wheels and this is the only way it can be done such that the Advans are kept and made more functional.
While I have amassed a bunch of parts, there are still a lot of random bits and pieces needed like a few front guard liners, headlight/bumper brackets, LHS front guard, underbody splash trays and very likely a new front bumper and bonnet.
Got all the bits home then realised the bonnet came off a E90 M3, which doesn't fit E92/E93, so back it went. The seller was great to deal with and refunded me no questions asked - he even gave me a damaged E92 M3 bonnet for free to make up for it.
Also got a pair of damaged bumpers while I was there. Have since vultured all the miscellaneous bits from them, like side mounts and headlight washer nozzles and covers, but I think they will be destined for the bin as a brand new one from BMW Sydney is about $1,300 AUD shipped, which isn't as crazy as I thought dealer pricing would be on a M3 front bumper. Not sure how fixable the white bonnet is, as e9x bonnets are aluminium and most of the damage is near the body lines, but I'll see how close I can get it before I start looking for one that's in good shape.
This M3 widebody replica project is a massive undertaking and basically means the car will be cut up and completely resprayed. I don't intend on doing this until I have everything and also have someone in line who can do a perfect job with the rear quarters. The workmanship on the rear quarters and paintjob are what will either take this build to the next level or completely destroy it, so I'm not taking this lightly.
I am considering changing the exterior colour to BMW Individual Brilliant White, as it's a bit different to plain old white, but close enough to Alpine White 3 so the door jambs etc don't look too obvious. I do not want a full respray lol. The Brilliant White colour uses Alpine White 3 as the base, but has a pearl/metallic top added on top. Here's some pics of what I'm aiming for colour wise, minus the CF roof of course.
I would also like to graft the 335i lower section into the M3 bumper as I think it looks far nicer than the E9x M3 rear grille/diffuser/exhaust section). I think something like this will look awesome.