I've seen some GC8's with the wide body kits, and I gotta say, the rear doors flared do look pretty crazy. Tough to do, but not undoable.
Ignore the kit, I'm not a fan of it either, but the rear door is exactly what I had in mind, albeit running back in flat due to lack of wbk skirts.
I could do the bolt-on flares, but to make it run flush i'll still need to flare the rear door, otherwise it'll look silly, this sharp flare coming out at a 70 degree angle right before the rear door.
There's plenty of meat in the stock flares, it's quite thick metal, so there'd be a fair bit to work with when thinning and extending, given that I'd be chasing somewhere between 30-50mm. Ah, pipe dreams are nice, arent they?