SAM unit?
 

Issue with E280 CDI ( 2006)
Front lights constantly on even when set to off or auto,screen wash level warning light on even when reservoir is full ( been like this for a couple of months),rear licence plate lights not working,3rd tail light not working & boot can only be opened via emergency key.( since yesterday)Can anyone diagnose likely cause/solution?

the harness on the left side trunk lid hinge is broken, this will cause 3rd brake light and interior trunk lights and opening trunk from inside switch al inoperable.
for your headlights always being on....check your settings in the cluster for "lighting" maybe set to constant?

Thanks chassis221, i will have a look at that.