Aftermarket warranty?

Hello everyone, I am new to the forum and was wondering if anyone could recomend a good one? I bought a 740i sport off a guy cheap who did absolutely no maintainance to the car. He had a printout from the dealer saying it was the Vanos. I shopped around right after the I bought to different mechanics and found one I trust sorta. He said it might be the cam shaft sensor. He pulled the motor apart and lets say he literally opened pandoras box. It needs timing chains and guide rails,oil and water pumps, all four cats are clogged and pre-cats, also needs o2 sensor, and intake manifold is burnt. So as u can see my first BMW expierience has not been good. Any help would greatly be appreciated! I've checked out warrantys on E38.org but they look like spam.

Aftermarket warranties were always a challenge to find once your car was out of factory warranty. On a 10+ year old car you might not be able to find anything.

This is what the mechanic pulled out out the cats

They were all blocked with these charcol like substance. The mechanic said Im lucky the car didnt catch fire!!!!!