Safe hack money method ?
1 . Using "How to Save Most Spawned Cars Online Tutorial" to spawn cars like adders.
2 . Sell it.
3 . ???
4 . Profit.
Nothing is really safe. R* has transaction logs on everything you receive, wouldn't be hard to see someone continuing to sell Adders without any logs of actually purchasing one.
IMHO, this is quite safe :
downgrade to 1.24
use equility menu
drop money on self
keep money on hand, don't deposit to bank
upgrade back to latest version