firstly it wasn't that bad of a smash, no other part of the car was damaged other than the engine compartment, and yes it has been on the jig and aligned, my husband is a panel beater and paint sprayer by trade and its the only thing he's done for 30 years. It isn't a cat C as it was not recorded, the guy had, had the car from new and couldn't afford to repair it or claim on his insurance. yes it was worth doing as we have only paid for parts as my husbands time is free.
Yes I will feel safe driving it, as my husband is a perfectionist and it's had everything new that it's needed, and if anything is now a stronger, better car
Unless you MCS is very different to mine your ecu (engine control unit) is in the engine bay between the fuse box and the airbox. Your bc1 (body control unit) is behind the trim in The drivers foot well. The MRS control box is by the hand brake under the trim
If it has had that bad a crash you will need to run a full diagnostic on it. Using the bmw or auto logic software and reset the system or it will not let you start the car
You will need to check all the srs/mrs system out before you try to reset it
Re all of that, right yep I'm at home and he's at our unit and hes just looked and all is exactly where you said, I think we just don't know the terms for things.
What does each thing do ? ECU, BCU and MRS ? We have a mechanic friend from the Main Dealer where my husband works who is going to come have a look too, Thank you so much for your help so far