[Probleemkind]

Ah, so driving it around would let me shut the car off right when I got back, but when I put the key in again it would lock it and not let me remove it. I figured out the real issue though!

This E60 is a drift car, it has the wisefab angle kit for an E90 installed in the front, modified to fit the E60. I used the E90 wheel speed sensors and changed the connectors to fit E60, and here lies the problem. They were sending bogus signals to the DSC making the car think it is in motion when it is stopped, which causes all sorts of weird behavior because the CAS won’t let you remove the key or let the car go to sleep if it is moving. I disconnected the sensors and immediately problem went away. I will have to figure out how to adapt the E60 sensors to the wisefab knuckle.

Who would've guessed haha, good thing you found the problem!