Si525d

HELP!!!
Bought the car in MAY, 525d on a 55 plate and its loads a stoopid faults.
1 Airbag lights on
2 Passenger seat bongs so have to have the belt plugged in all the time
3 I drive not working properly
Satnav doesn't work
DVD doesn't work
Radio rec isn't great
4 fault "Key not in ignition car maynot restart" . So now I can lock the car and open the boot but can't open the car. Sometimes it will open and sometimes it will start but most of the time nothing comes on when I turn the ignition on. I don't have a rechargeable battery diamond key I've the 1 pictured below.
THE previous owner had an auxiliary plug fitted and cables to the boot for a sub box also change the Angel Eyes from standard to Blue.
Could it all be connected?
Or has anybody had similar problems?
Any help appreciated 👍🙏🙂

JayArras

Did you know all this when you bought the car?

JCapirote

The airbag lights on my e39 used to be a faulty connector under the drivers seat, along with the seat belt bong I’d suggest searching the connection of plugs around that seat, unplug and clean up the connectors and see if the issue is resolved. Being careful not to short anything out obviously and setting any of the safety systems off, airbags, seat belt tension era etc
the radio reception on my e60 is crap too, probably needs a new aerial, but as I don’t tend to listen to the radio doesn’t really bother me
auxiliaries plug unlikely to cause the issues, the replacement lights may cause canbus issues but that likely showing as blown bulbs
hope some of this resolved some of your issues 👍👍