Great car Ben!
I wanted one of these ( the 33 to be more precise ) for a daily-driver here in London, but the missus wouldn't have it. If I stuck an AUDI or Volvo badge on it she would probably think it was fine, though!
E = Extinguisher 'switch'. Mandatory in most race cars. Its connected to the handle outside too ( for the marshalls to activate in an emergency ).
Inside electrical cut-off switch is in the dash eyeball vent. There's one outside too.