Haha unbelievable.

I said to them - "so if i disconnect the battery to install something, eg. gauges, I will have to come into Subaru to get it reset?" To which the foreign sounding woman on the end of the phone answered - "yes thats correct"

I'm no mechanic. However i am a mechanical engineer. And i dont think it would take me 3 months to install some gauges.
That said, I would probably get a workshop to do it for peace of mind anyway, and if it took them 3 months i'd be mighty pissed. Not to mention 3 months worth of labour costs.

Thanks guys appreciate the feedback!