You could tie in the first three together but wont be cheap as you'll need a new screen as thats where the rain sensor is, obv the mirror needs replacing as well! you'll also need a new headlight control switch for the auto-lights but its certainly do-able.
MFSW much easier but again wont be cheap, new wheel and possibly new steering wheel ECU and slip ring may be required, And of course access to VAG-COM, All very do-able though.
I just completed retro-fitting auto-dimming exterior door mirrors, a ****** of a job but well worth the effort now its all done I feel.:icon_thumright: