i have firends who have the GT500 and Lightning trucks. I have heard and seen some of the issues you are talkin about. But the problem was idiots who either

A. turn the boost up with out a proper tune, wideband, and better cooling system.

or

B. run them to the ground without the proper maintenance

yes. anything w12 is gunna be scary to fix lol! just think of a head job on those fuckers lol!