Do you mean the 1% “rule”? While it gets mentioned a LOT online, it’s more of a guideline/rule of thumb than something set in stone. It’s based on MSRP; however, it’s not really the best way to gauge a deal. For example, last month many 3 series leases were going for $2-300 month, whereas 1% of MSRP could have been $400-500.
@CombatWombat to really evaluate this deal, you’ll need to provide more info. Did the dealership give you a lease worksheet by chance? If so, throw a pic up so people can provide more detailed feedback!