Okay, going to post this as I've tested multiple times before the patch came out that the unlimited health option seems to be the main culprit for the crashing anyone has.
Tried quicksave, manual save, the autosave when transitions occur, all of which crash when unlimited health is active.
Turned off, saves work perfectly fine. Patch comes out, same thing. If anyone looks into the char info when unlimited health is on, you'll notice 9999 health showing. When you turn it off, it goes down to 100.
IF you use unlimited health after using anything that increases your health (specifically one of the engineering items, don't want to spoil it beyond that) you will go back down to 100 health, regardless of whatever it was set to.
This is not a complaint, this is simply a warning to anyone who is complaining about the hp modification, as more than likely the game is probably detecting a number beyond 9999, and as most would know, 9999 seems to be the highest number it is capable of detecting for money, racing certs, and just about anything else (even ammunition for the cars, minigun ammo and rockets.)
So in lamen's terms, any save happening while that's on is probably wigging the thing out with a number beyond that, so it thinks it's corrupt or some such (not claiming to know all details, Caliber would be able to answer that or PW) Turn it off, quick save, manual save, w/e, transition, turn back on. If you think it's annoying you have to do that each time, either stop complaining and wait til Caliber tracks the problem down, or use the engineering recipe you get (quest from wellspring bar, old man in booth, forget his name)
Also have noticed in some games turning on trainer takes some effort to get to acknowledge (holding down f1) Again, not complaining, just sharing info, same for unlimited health, some button pressing needs to be held down, don't think it's the trainer, probably your comp configuration or hardware.
I do not claim to know everything about this, it's just from personal experience, take it as you will.
Yup, pretty the same conclusion i came to back a few pages. Glad to see i'm not the only one with the same idea
Also, as far as "holding down f1" goes. You'll find that it's just taking a moment to initialise, and if you leave it it will activate anyway. The more complex a game is the more stuff it has to do to 'hook in' so that it can make everything work properly.